Features
•Single 2.7V to 3.6V Supply
•RapidS Serial Interface: 66MHz Maximum Clock Frequency
– SPI Compatible Modes 0 and 3
•User Configurable Page Size
– 256-Bytes per Page
– 264-Bytes per Page
– Page Size Can Be Factory Pre-configured for 256-Bytes
•Page Program Operation
– Intelligent Programming Operation
– 1,024 Pages (256/264-Bytes/Page) Main Memory
•Flexible Erase Options
– Page Erase (256-Bytes)
– Block Erase (2-Kbytes)
– Sector Erase (32-Kbytes)
– Chip Erase (2-Mbits)
•One SRAM Data Buffer (256/264-Bytes)
•Continuous Read Capability through Entire Array
– Ideal for Code Shadowing Applications
•Low-power Dissipation
– 7mA Active Read Current Typical
–25μA Standby Current Typical
–15μA Deep Power-down Typical
•Hardware and Software Data Protection Features
– Individual Sector
•Sector Lockdown for Secure Code and Data Storage
– Individual Sector
•Security: 128-byte Security Register
– 64-byte User Programmable Space
– Unique 64-byte Device Identifier
•JEDEC Standard Manufacturer and Device ID Read
•100,000 Program/Erase Cycles Per Page Minimum
•Data Retention – 20 Years
•Industrial Temperature Range
•Green (Pb/Halide-free/RoHS Compliant) Packaging Options
Description
The AT45DB021D is a 2.7V, serial-interface Flash memory ideally suited for a wide
variety of digital voice-, image-, program code- and data-storage applications. The
AT45DB021D supports RapidS™ serial interface for applications requiring very high
speed operations. RapidS serial interface is SPI compatible for frequencies up to
66MHz. Its 2-,162-,688-bits of memory are organized as 1,024-pages of 256-bytes or
264-bytes each. In addition to the main memory, the AT45DB021D also contains one
SRAM buffer of 256-/264-bytes. EEPROM emulation (bit or byte alterability) is easily
handled with a self-contained three step read-modify-write operation. Unlike conven-
tional Flash memories that are accessed randomly with multiple address lines and a
parallel interface, the DataFlash® uses a RapidS serial interface to sequentially
access its data. The simple sequential access dramatically reduces active pin count,
facilitates hardware layout, increases system reliability, minimizes switching noise,
and reduces package size.
2-megabit
2.7V Minimum
DataFlash
AT45DB021D
(Not Recommended
for New Designs)
3638M–DFLASH–5/2013
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3638M–DFLASH–5/2013
AT45DB021D
The device is optimized for use in many commercial and industrial applications where high-density, low-pin count,
low-voltage and low-power are essential.
To allow for simple in-system reprogrammability, the AT45DB021D does not require high input voltages for
programming. The device operates from a single power supply, 2.7V to 3.6V, for both the program and read
operations. The AT45DB021D is enabled through the chip select pin (CS) and accessed via a three-wire interface
consisting of the Serial Input (SI), Serial Output (SO), and the Serial Clock (SCK).
All programming and erase cycles are self-timed.
1. Pin Configurations and Pinouts
Table 1-1. Pin Configurations
Symbol Name and Function
Asserte
d State Type
CS
Chip Select: Asserting the CS pin selects the device. When the CS pin is deasserted, the device will be
deselected and normally be placed in the standby mode (not Deep Power-Down mode), and the output
pin (SO) will be in a high-impedance state. When the device is deselected, data will not be accepted on
the input pin (SI).
A high-to-low transition on the CS pin is required to start an operation, and a low-to-high transition is
required to end an operation. When ending an internally self-timed operation such as a program or erase
cycle, the device will not enter the standby mode until the completion of the operation.
Low Input
SCK
Serial Clock: This pin is used to provide a clock to the device and is used to control the flow of data to
and from the device. Command, address, and input data present on the SI pin is always latched on the
rising edge of SCK, while output data on the SO pin is always clocked out on the falling edge of SCK.
– Input
SI Serial Input: The SI pin is used to shift data into the device. The SI pin is used for all data input including
command and address sequences. Data on the SI pin is always latched on the rising edge of SCK. – Input
SO Serial Output: The SO pin is used to shift data out from the device. Data on the SO pin is always clocked
out on the falling edge of SCK. – Output
WP
Write Protect: When the WP pin is asserted, all sectors specified for protection by the Sector Protection
Register will be protected against program and erase operations regardless of whether the Enable
Sector Protection command has been issued or not. The WP pin functions independently of the software
controlled protection method. After the WP pin goes low, the content of the Sector Protection Register
cannot be modified.
If a program or erase command is issued to the device while the WP pin is asserted, the device will
simply ignore the command and perform no operation. The device will return to the idle state once the CS
pin has been deasserted. The Enable Sector Protection command and Sector Lockdown command,
however, will be recognized by the device when the WP pin is asserted.
The WP pin is internally pulled-high and may be left floating if hardware controlled protection will not be
used. However, it is recommended that the WP pin also be externally connected to VCC whenever
possible.
Low Input
RESET
Reset: A low state on the reset pin (RESET) will terminate the operation in progress and reset the
internal state machine to an idle state. The device will remain in the reset condition as long as a low level
is present on the RESET pin. Normal operation can resume once the RESET pin is brought back to a
high level.
The device incorporates an internal power-on reset circuit, so there are no restrictions on the RESET pin
during power-on sequences. If this pin and feature are not utilized it is recommended that the RESET pin
be driven high externally.
Low Input
VCC
Device Power Supply: The VCC pin is used to supply the source voltage to the device.
Operations at invalid VCC voltages may produce spurious results and should not be attempted. – Power
GND Ground: The ground reference for the power supply. GND should be connected to the system ground. – Groun
d
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3638M–DFLASH–5/2013
AT45DB021D
Notes: 1. The metal pad on the bottom of the UDFN package is floating. This pad can be a “No Connect” or connected to
GND
Figure 1-3. Block Diagram
Figure 1-1. SOIC Top View Figure 1-2. UDFN Top View(1)
1
2
3
4
8
7
6
5
SI
SCK
RESET
CS
SO
GND
VCC
WP
SI
SCK
RESET
CS
SO
GND
VCC
WP
8
7
6
5
1
2
3
4
FLASH MEMORY ARRAY
BUFFER (256-/264-BYTES)
I/O INTERFACE
SCK
CS
RESET
VCC
GND
WP
SO SI
PAGE (256-/264-BYTES)
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AT45DB021D
2. Memory Array
To provide optimal flexibility, the memory array of the AT45DB021D is divided into three levels of granularity
comprising of sectors, blocks, and pages. The “Memory Architecture Diagram” illustrates the breakdown of each
level and details the number of pages per sector and block. All program operations to the DataFlash occur on a
page-by-page basis. The erase operations can be performed at the chip, sector, block or page level.
Figure 2-1. Memory Architecture Diagram
3. Device Operation
The device operation is controlled by instructions from the host processor. The list of instructions and their
associated opcodes are contained in Tables 13-1 through 13-7. A valid instruction starts with the falling edge of CS
followed by the appropriate 8-bit opcode and the desired buffer or main memory address location. While the CS pin
is low, toggling the SCK pin controls the loading of the opcode and the desired buffer or main memory address
location through the SI (serial input) pin. All instructions, addresses, and data are transferred with the most
significant bit (MSB) first.
Buffer addressing for the DataFlash standard page size (264-bytes) is referenced in the datasheet using the
terminology BFA8 - BFA0 to denote the nine address bits required to designate a byte address within a buffer.
Main memory addressing is referenced using the terminology PA9 - PA0 and BA8 - BA0, where PA9 - PA0
denotes the 10-address bits required to designate a page address and BA8 - BA0 denotes the nine address bits
required to designate a byte address within the page.
For the “Power of 2” binary page size (256-bytes), the Buffer addressing is referenced in the datasheet using the
conventional terminology BFA7 - BFA0 to denote the eight address bits required to designate a byte address within
a buffer. Main memory addressing is referenced using the terminology A17 - A0, where A17 - A8 denotes the 10-
address bits required to designate a page address and A7 - A0 denotes the eight address bits required to
designate a byte address within a page.
SECTOR 0a = 8 Pages
2,048 / 2,112-bytes
SECTOR 0b = 120 Pages
31,744 / 32,726-bytes
Block = 2,048 / 2,112-bytes
8 Pages
SECTOR 0a
SECTOR 0b
Page = 256 / 264-bytes
PAGE 0
PAGE 1
PAGE 6
PAGE 7
PAGE 8
PAGE 9
PAGE 1,022
PAGE 1,023
BLOCK 0
PAGE 14
PAGE 15
PAGE 16
PAGE 17
PAGE 18
BLOCK 1
SECTOR ARCHITECTURE BLOCK ARCHITECTURE PAGE ARCHITECTURE
BLOCK 0
BLOCK 1
BLOCK 14
BLOCK 15
BLOCK 16
BLOCK 17
BLOCK 126
BLOCK 127
BLOCK 30
BLOCK 31
BLOCK 32
BLOCK 33
SECTOR 1
SECTOR 7 = 128 Pages
32,768 / 33,792-bytes
BLOCK 2
SECTOR 1 = 128 Pages
32,768 / 33,792-bytes
SECTOR 6 = 128 Pages
32,768 / 33,792-bytes
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AT45DB021D
4. Read Commands
By specifying the appropriate opcode, data can be read from the main memory or from the SRAM data buffer. The
DataFlash supports RapidS protocols for Mode 0 and Mode 3. Please refer to the “Detailed Bit-level Read Timing”
diagrams in this datasheet for details on the clock cycle sequences for each mode.
4.1 Continuous Array Read (Legacy Command – E8H): Up to 66MHz
By supplying an initial starting address for the main memory array, the Continuous Array Read command can be
utilized to sequentially read a continuous stream of data from the device by simply providing a clock signal; no
additional addressing information or control signals need to be provided. The DataFlash incorporates an internal
address counter that will automatically increment on every clock cycle, allowing one continuous read operation
without the need of additional address sequences. To perform a continuous read from the DataFlash standard
page size (264-bytes), an opcode of E8H must be clocked into the device followed by three address bytes (which
comprise the 24-bit page and byte address sequence) and four don’t care bytes. The first 10-bits (PA9 - PA0) of
the 19-bit address sequence specify which page of the main memory array to read, and the last 9-bits (BA8 - BA0)
of the 19-bit address sequence specify the starting byte address within the page. To perform a continuous read
from the binary page size (256-bytes), the opcode (E8H) must be clocked into the device followed by three address
bytes and four don’t care bytes. The first 10-bits (A17 - A8) of the 18-bits sequence specify which page of the main
memory array to read, and the last 8-bits (A7 - A0) of the 18-bits address sequence specify the starting byte
address within the page. The don’t care bytes that follow the address bytes are needed to initialize the read
operation. Following the don’t care bytes, additional clock pulses on the SCK pin will result in data being output on
the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the don’t care bytes, and the
reading of data. When the end of a page in main memory is reached during a Continuous Array Read, the device
will continue reading at the beginning of the next page with no delays incurred during the page boundary crossover
(the crossover from the end of one page to the beginning of the next page). When the last bit in the main memory
array has been read, the device will continue reading back at the beginning of the first page of memory. As with
crossing over page boundaries, no delays will be incurred when wrapping around from the end of the array to the
beginning of the array.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
maximum SCK frequency allowable for the Continuous Array Read is defined by the fCAR1 specification. The
Continuous Array Read bypasses the data buffer and leaves the contents of the buffer unchanged.
4.2 Continuous Array Read (High Frequency Mode – 0BH): Up to 66MHz
This command can be used with the serial interface to read the main memory array sequentially in high speed
mode for any clock frequency up to the maximum specified by fCAR1. To perform a continuous read array with the
page size set to 264-bytes, the CS must first be asserted then an opcode 0BH must be clocked into the device
followed by three address bytes and a dummy byte. The first 10-bits (PA9 - PA0) of the 19-bit address sequence
specify which page of the main memory array to read, and the last nine bits (BA8 - BA0) of the 19-bit address
sequence specify the starting byte address within the page. To perform a continuous read with the page size set to
256-bytes, the opcode, 0BH, must be clocked into the device followed by three address bytes (A17 - A0) and a
dummy byte. Following the dummy byte, additional clock pulses on the SCK pin will result in data being output on
the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When
the end of a page in the main memory is reached during a Continuous Array Read, the device will continue reading
at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover from
the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
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3638M–DFLASH–5/2013
AT45DB021D
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the
array. A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
maximum SCK frequency allowable for the Continuous Array Read is defined by the fCAR1 specification. The
Continuous Array Read bypasses the data buffer and leaves the contents of the buffer unchanged.
4.3 Continuous Array Read (Low Frequency Mode: 03H): Up to 33MHz
This command can be used with the serial interface to read the main memory array sequentially without a dummy
byte up to maximum frequencies specified by fCAR2. To perform a continuous read array with the page size set to
264-bytes, the CS must first be asserted then an opcode, 03H, must be clocked into the device followed by three
address bytes (which comprise the 24-bit page and byte address sequence). The first 10-bits (PA9 - PA0) of the
19-bit address sequence specify which page of the main memory array to read, and the last nine bits (BA8 - BA0)
of the 19-bit address sequence specify the starting byte address within the page. To perform a continuous read
with the page size set to 256-bytes, the opcode, 03H, must be clocked into the device followed by three address
bytes (A17 - A0). Following the address bytes, additional clock pulses on the SCK pin will result in data being
output on the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When
the end of a page in the main memory is reached during a Continuous Array Read, the device will continue reading
at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover from
the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the
array. A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The
Continuous Array Read bypasses the data buffer and leaves the contents of the buffer unchanged.
4.4 Main Memory Page Read
A main memory page read allows the user to read data directly from any one of the 2,048-pages in the main
memory, bypassing the data buffer and leaving the contents of the buffer unchanged. To start a page read from the
DataFlash standard page size (264-bytes), an opcode of D2H must be clocked into the device followed by three
address bytes (which comprise the 24-bit page and byte address sequence) and four don’t care bytes. The first 10-
bits (PA9 - PA0) of the 19-bit address sequence specify the page in main memory to be read, and the last 9-bits
(BA8 - BA0) of the 19-bit address sequence specify the starting byte address within that page. To start a page read
from the binary page size (256-bytes), the opcode D2H must be clocked into the device followed by three address
bytes and four don’t care bytes. The first 10-bits (A17 - A8) of the 18-bit sequence specify which page of the main
memory array to read, and the last 8-bits (A7 - A0) of the 18-bit address sequence specify the starting byte address
within the page. The don’t care bytes that follow the address bytes are sent to initialize the read operation.
Following the don’t care bytes, additional pulses on SCK result in data being output on the SO (serial output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the don’t care bytes, and the
reading of data. When the end of a page in main memory is reached, the device will continue reading back at the
beginning of the same page. A low-to-high transition on the CS pin will terminate the read operation and tri-state
the output pin (SO). The maximum SCK frequency allowable for the Main Memory Page Read is defined by the
fSCK specification. The Main Memory Page Read bypasses the data buffer and leaves the contents of the buffer
unchanged.
4.5 Buffer Read
The SRAM data buffer can be accessed independently from the main memory array, and utilizing the Buffer Read
Command allows data to be sequentially read directly from the buffer. Two opcodes, D4H or D1H, can be used for
the Buffer Read Command. The use of each opcode depends on the maximum SCK frequency that will be used to
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3638M–DFLASH–5/2013
AT45DB021D
read data from the buffer. The D4H opcode can be used at any SCK frequency up to the maximum specified by
fCAR1. The D1H opcode can be used for lower frequency read operations up to the maximum specified by fCAR2.
To perform a buffer read from the DataFlash standard buffer (264-bytes), the opcode must be clocked into the
device followed by three address bytes comprised of 15 don’t care bits and 9 buffer address bits (BFA8 - BFA0).
To perform a buffer read from the binary buffer (256-bytes), the opcode must be clocked into the device followed
by three address bytes comprised of 16 don’t care bits and eight buffer address bits (BFA7 - BFA0). Following the
address bytes, one don’t care byte must be clocked in to initialize the read operation. The CS pin must remain low
during the loading of the opcode, the address bytes, the don’t care bytes, and the reading of data. When the end of
a buffer is reached, the device will continue reading back at the beginning of the buffer. A low-to-high transition on
the CS pin will terminate the read operation and tri-state the output pin (SO).
5. Program and Erase Commands
5.1 Buffer Write
Data can be clocked in from the input pin (SI) into the buffer. To load data into the DataFlash standard buffer (264-
bytes), a 1-byte opcode, 84H, must be clocked into the device followed by three address bytes comprised of 15
don’t care bits and nine buffer address bits (BFA8 - BFA0). The nine buffer address bits specify the first byte in the
buffer to be written. To load data into the binary buffers (256-bytes each), a 1-byte opcode, 84H, must be clocked
into the device followed by three address bytes comprised of 16 don’t care bits and eight buffer address bits (BFA7
- BFA0). The eight buffer address bits specify the first byte in the buffer to be written. After the last address byte
has been clocked into the device, data can then be clocked in on subsequent clock cycles. If the end of the data
buffer is reached, the device will wrap around back to the beginning of the buffer. Data will continue to be loaded
into the buffer until a low-to-high transition is detected on the CS pin.
5.2 Buffer to Main Memory Page Program with Built-in Erase
Data written into the buffer can be programmed into the main memory. A 1-byte opcode, 83H, must be clocked into
the device. For the DataFlash standard page size (264-bytes), the opcode must be followed by three address bytes
consist of five don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be
written and nine don’t care bits. To perform a buffer to main memory page program with built-in erase for the binary
page size (256-bytes), the opcode 83H must be clocked into the device followed by three address bytes consisting
of six don’t care bits, 10 page address bits (A17 - A8) that specify the page in the main memory to be written and
eight don’t care bits. When a low-to-high transition occurs on the CS pin, the part will first erase the selected page
in main memory (the erased state is a logic 1) and then program the data stored in the buffer into the specified
page in main memory. Both the erase and the programming of the page are internally self-timed and should take
place in a maximum time of tEP. During this time, the status register will indicate that the part is busy.
5.3 Buffer to Main Memory Page Program without Built-in Erase
A previously-erased page within main memory can be programmed with the contents of the buffer. A 1-byte
opcode, 88H, must be clocked into the device. For the DataFlash standard page size (264-bytes), the opcode must
be followed by three address bytes consist of five don’t care bits, 10 page address bits (PA9 - PA0) that specify the
page in the main memory to be written and nine don’t care bits. To perform a buffer to main memory page program
without built-in erase for the binary page size (256-bytes), the opcode 88H must be clocked into the device
followed by three address bytes consisting of six don’t care bits, 10 page address bits (A17 - A8) that specify the
page in the main memory to be written and eight don’t care bits. When a low-to-high transition occurs on the CS
pin, the part will program the data stored in the buffer into the specified page in the main memory. It is necessary
that the page in main memory that is being programmed has been previously erased using one of the erase
commands (Page Erase or Block Erase). The programming of the page is internally self-timed and should take
place in a maximum time of tP. During this time, the status register will indicate that the part is busy.
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3638M–DFLASH–5/2013
AT45DB021D
5.4 Page Erase
The Page Erase command can be used to individually erase any page in the main memory array allowing the
Buffer to Main Memory Page Program to be utilized at a later time. To perform a page erase in the DataFlash
standard page size (264-bytes), an opcode of 81H must be loaded into the device, followed by three address bytes
comprised of five don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be
erased and nine don’t care bits. To perform a page erase in the binary page size (256-bytes), the opcode 81H must
be loaded into the device, followed by three address bytes consist of six don’t care bits, 10 page address bits (A17
- A8) that specify the page in the main memory to be erased and eight don’t care bits. When a low-to-high transition
occurs on the CS pin, the part will erase the selected page (the erased state is a logical 1). The erase operation is
internally self-timed and should take place in a maximum time of tPE. During this time, the status register will
indicate that the part is busy.
5.5 Block Erase
A block of eight pages can be erased at one time. This command is useful when large amounts of data has to be
written into the device. This will avoid using multiple Page Erase Commands. To perform a block erase for the
DataFlash standard page size (264-bytes), an opcode of 50H must be loaded into the device, followed by three
address bytes comprised of five don’t care bits, seven page address bits (PA9 -PA3) and 12 don’t care bits. The
seven page address bits are used to specify which block of eight pages is to be erased. To perform a block erase
for the binary page size (256-bytes), the opcode 50H must be loaded into the device, followed by three address
bytes consisting of six don’t care bits, seven page address bits (A17 - A11) and 11 don’t care bits. The 9-page
address bits are used to specify which block of eight pages is to be erased. When a low-to-high transition occurs
on the CS pin, the part will erase the selected block of eight pages. The erase operation is internally self-timed and
should take place in a maximum time of tBE. During this time, the status register will indicate that the part is busy.
Table 5-1. Block Erase Addressing
5.6 Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory. There are four
sectors and only one sector can be erased at one time. To perform sector 0a or sector 0b erase for the DataFlash
standard page size (264-bytes), an opcode of 7CH must be loaded into the device, followed by three address bytes
comprised of five don’t care bits, seven page address bits (PA9 - PA3) and 12 don’t care bits. To perform a sector
1-7 erase, the opcode 7CH must be loaded into the device, followed by three address bytes comprised of five don’t
care bits, three page address bits (PA9 - PA7) and 16 don’t care bits. To perform sector 0a or sector 0b erase for
PA9/
A17
PA8/
A16
PA7/
A15
PA6/
A14
PA5/
A13
PA4/
A12
PA3/
A11
PA2/
A10
PA1/
A9
PA0/
A8 Block
0000000XXX0
0000001XXX1
0000010XXX2
0000011XXX3
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1111100XXX124
1111101XXX125
1111110XXX126
1111111XXX127
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3638M–DFLASH–5/2013
AT45DB021D
the binary page size (25-bytes), an opcode of 7CH must be loaded into the device, followed by three address bytes
comprised of six don’t care bits and seven page address bits (A17 - A11) and 11 don’t care bits. To perform a
sector 1-seven erase, the opcode 7CH must be loaded into the device, followed by three address bytes comprised
of six don’t care bit and three page address bits (A17 - A15) and 16 don’t care bits. The page address bits are used
to specify any valid address location within the sector which is to be erased. When a low-to-high transition occurs
on the CS pin, the part will erase the selected sector. The erase operation is internally self-timed and should take
place in a maximum time of tSE. During this time, the status register will indicate that the part is busy.
Table 5-2. Sector Erase Addressing
5.7 Chip Erase
The entire main memory can be erased at one time by using the Chip Erase command.
To execute the Chip Erase command, a 4-byte command sequence C7H, 94H, 80H and 9AH must be clocked into
the device. Since the entire memory array is to be erased, no address bytes need to be clocked into the device,
and any data clocked in after the opcode will be ignored. After the last bit of the opcode sequence has been
clocked in, the CS pin can be deasserted to start the erase process. The erase operation is internally self-timed
and should take place in a time of tCE. During this time, the Status Register will indicate that the device is busy.
The Chip Erase command will not affect sectors that are protected or locked down; the contents of those sectors
will remain unchanged. Only those sectors that are not protected or locked down will be erased.
The WP pin can be asserted while the device is erasing, but protection will not be activated until the internal erase
cycle completes.
Table 5-3. Chip Erase Command
Figure 5-1. Chip Erase
PA9/
A17
PA8/
A16
PA7/
A15
PA6/
A14
PA5/
A13
PA4/
A12
PA3/
A11
PA2/
A10
PA1/
A9
PA0/
A8 Sector
0000000XXX0a
0000001XXX0b
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
011XXXXXXX5
100XXXXXXX6
111XXXXXXX7
Command Byte 1 Byte 2 Byte 3 Byte 4
Chip Erase C7H 94H 80H 9AH
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Each transition
represents 8 bits
SI
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5.8 Main Memory Page Program Through Buffer
This operation is a combination of the Buffer Write and Buffer to Main Memory Page Program with Built-in Erase
operations. Data is first clocked into the buffer from the input pin (SI) and then programmed into a specified page in
the main memory. To perform a main memory page program through buffer for the DataFlash standard page size
(264-bytes), a 1-byte opcode, 82H, must first be clocked into the device, followed by three address bytes. The
address bytes are comprised of five don’t care bits, 10 page address bits, (PA9 - PA0) that select the page in the
main memory where data is to be written, and nine buffer address bits (BFA8 - BFA0) that select the first byte in
the buffer to be written. To perform a main memory page program through buffer for the binary page size (256-
bytes), the opcode 82H must be clocked into the device followed by three address bytes consisting of six don’t care
bits, 10 page address bits (A17 - A8) that specify the page in the main memory to be written, and eight buffer
address bits (BFA7 - BFA0) that selects the first byte in the buffer to be written. After all address bytes are clocked
in, the part will take data from the input pins and store it in the specified data buffer. If the end of the buffer is
reached, the device will wrap around back to the beginning of the buffer. When there is a low-to-high transition on
the CS pin, the part will first erase the selected page in main memory to all ones and then program the data stored
in the buffer into that memory page. Both the erase and the programming of the page are internally self-timed and
should take place in a maximum time of tEP. During this time, the status register will indicate that the part is busy.
6. Sector Protection
Two protection methods, hardware and software controlled, are provided for protection against inadvertent or
erroneous program and erase cycles. The software controlled method relies on the use of software commands to
enable and disable sector protection while the hardware controlled method employs the use of the Write Protect
(WP) pin. The selection of which sectors that are to be protected or unprotected against program and erase
operations is specified in the nonvolatile Sector Protection Register. The status of whether or not sector protection
has been enabled or disabled by either the software or the hardware controlled methods can be determined by
checking the Status Register.
6.1 Software Sector Protection
6.1.1 Enable Sector Protection Command
Sectors specified for protection in the Sector Protection Register can be protected from program and erase
operations by issuing the Enable Sector Protection command. To enable the sector protection using the software
controlled method, the CS pin must first be asserted as it would be with any other command. Once the CS pin has
been asserted, the appropriate 4-byte command sequence must be clocked in via the input pin (SI). After the last
bit of the command sequence has been clocked in, the CS pin must be deasserted after which the sector
protection will be enabled.
Table 6-1. Enable Sector Protection Command
Figure 6-1. Enable Sector Protection
Command Byte 1 Byte 2 Byte 3 Byte 4
Enable Sector Protection 3DH 2AH 7FH A9H
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Each transition
represents 8 bits
SI
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6.1.2 Disable Sector Protection Command
To disable the sector protection using the software controlled method, the CS pin must first be asserted as it would
be with any other command. Once the CS pin has been asserted, the appropriate 4-byte sequence for the Disable
Sector Protection command must be clocked in via the input pin (SI). After the last bit of the command sequence
has been clocked in, the CS pin must be deasserted after which the sector protection will be disabled. The WP pin
must be in the deasserted state; otherwise, the Disable Sector Protection command will be ignored.
Table 6-2. Disenable Sector Protection Command
Figure 6-2. Disable Sector Protection
6.1.3 Various Aspects About Software Controlled Protection
Software controlled protection is useful in applications in which the WP pin is not or cannot be controlled by a host
processor. In such instances, the WP pin may be left floating (the WP pin is internally pulled high) and sector
protection can be controlled using the Enable Sector Protection and Disable Sector Protection commands.
If the device is power cycled, then the software controlled protection will be disabled. Once the device is powered
up, the Enable Sector Protection command should be reissued if sector protection is desired and if the WP pin is
not used.
7. Hardware Controlled Protection
Sectors specified for protection in the Sector Protection Register and the Sector Protection Register itself can be
protected from program and erase operations by asserting the WP pin and keeping the pin in its asserted state.
The Sector Protection Register and any sector specified for protection cannot be erased or reprogrammed as long
as the WP pin is asserted. In order to modify the Sector Protection Register, the WP pin must be deasserted. If the
WP pin is permanently connected to GND, then the content of the Sector Protection Register cannot be changed.
If the WP pin is deasserted, or permanently connected to VCC, then the content of the Sector Protection Register
can be modified.
The WP pin will override the software controlled protection method but only for protecting the sectors. For example,
if the sectors were not previously protected by the Enable Sector Protection command, then simply asserting the
WP pin would enable the sector protection within the maximum specified tWPE time. When the WP pin is
deasserted; however, the sector protection would no longer be enabled (after the maximum specified tWPD time) as
long as the Enable Sector Protection command was not issued while the WP pin was asserted. If the Enable
Sector Protection command was issued before or while the WP pin was asserted, then simply deasserting the WP
pin would not disable the sector protection. In this case, the Disable Sector Protection command would need to be
issued while the WP pin is deasserted to disable the sector protection. The Disable Sector Protection command is
also ignored whenever the WP pin is asserted.
A noise filter is incorporated to help protect against spurious noise that may inadvertently assert or deassert the
WP pin.
Command Byte 1 Byte 2 Byte 3 Byte 4
Disable Sector Protection 3DH 2AH 7FH 9AH
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Each transition
represents 8 bits
SI
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The table below details the sector protection status for various scenarios of the WP pin, the Enable Sector
Protection command, and the Disable Sector Protection command.
Figure 7-1. WP Pin and Protection Status
Table 7-1. WP Pin and Protection Status
7.1 Sector Protection Register
The nonvolatile Sector Protection Register specifies which sectors are to be protected or unprotected with either
the software or hardware controlled protection methods. The Sector Protection Register contains 8-bytes of data,
of which byte locations zero through seven contain values that specify whether sectors zero through seven will be
protected or unprotected. The Sector Protection Register is user modifiable and must first be erased before it can
be reprogrammed. Table 7-3 illustrates the format of the Sector Protection Register
Table 7-2. Sector Protection Register.
Table 7-3. Sector 0 (0a, 0b)
Note: 1. The default value for bytes 0 through 7 when shipped from Adesto is 00H
x = don’t care
Time
Period WP Pin
Enable Sector Protection
Command
Disable Sector
Protection Command
Sector
Protection Status
Sector
Protection
Register
1 High
Command Not Issued Previously
–
Issue Command
X
Issue Command
–
Disabled
Disabled
Enabled
Read/Write
Read/Write
Read/Write
2 Low X X Enabled Read Only
3 High
Command Issued During Period 1
or 2
–
Issue Command
Not Issued Yet
Issue Command
–
Enabled
Disabled
Enabled
Read/Write
Read/Write
Read/Write
WP
12
3
Sector Number 0 (0a, 0b) 1 to 7
Protected See Table 7-3 FFH
Unprotected 00H
0a 0b
Bit 3, 2
Data
Value
(Page 0-7) (Page 8-127)
Bit 7, 6 Bit 5, 4 Bit 1, 0
Sectors 0a, 0b Unprotected 00 00 xx xx 0xH
Protect Sector 0a 11 00 xx xx CxH
Protect Sector 0b (Page 8-127) 00 11 xx xx 3xH
Protect Sectors 0a (Page 0-7), 0b (Page 8-127)(1) 11 11 xx xx FxH
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7.1.1 Erase Sector Protection Register Command
In order to modify and change the values of the Sector Protection Register, it must first be erased using the Erase
Sector Protection Register command.
To erase the Sector Protection Register, the CS pin must first be asserted as it would be with any other command.
Once the CS pin has been asserted, the appropriate 4-byte opcode sequence must be clocked into the device via
the SI pin. The 4-byte opcode sequence must start with 3DH and be followed by 2AH, 7FH, and CFH. After the last
bit of the opcode sequence has been clocked in, the CS pin must be deasserted to initiate the internally self-timed
erase cycle. The erasing of the Sector Protection Register should take place in a time of tPE, during which time the
Status Register will indicate that the device is busy. If the device is powered-down before the completion of the
erase cycle, then the contents of the Sector Protection Register cannot be guaranteed.
The Sector Protection Register can be erased with the sector protection enabled or disabled. Since the erased
state (FFH) of each byte in the Sector Protection Register is used to indicate that a sector is specified for
protection, leaving the sector protection enabled during the erasing of the register allows the protection scheme to
be more effective in the prevention of accidental programming or erasing of the device. If for some reason an
erroneous program or erase command is sent to the device immediately after erasing the Sector Protection
Register and before the register can be reprogrammed, then the erroneous program or erase command will not be
processed because all sectors would be protected.
Table 7-4. Erase Sector Protection Register Command
Figure 7-2. Erase Sector Protection Register
7.1.2 Program Sector Protection Register Command
Once the Sector Protection Register has been erased, it can be reprogrammed using the Program Sector
Protection Register command.
To program the Sector Protection Register, the CS pin must first be asserted and the appropriate 4-byte opcode
sequence must be clocked into the device via the SI pin. The 4-byte opcode sequence must start with 3DH and be
followed by 2AH, 7FH, and FCH. After the last bit of the opcode sequence has been clocked into the device, the
data for the contents of the Sector Protection Register must be clocked in. As described in Section 7.1, the Sector
Protection Register contains 4-bytes of data, so 4-bytes must be clocked into the device. The first byte of data
corresponds to sector zero, the second byte corresponds to sector one, the third byte corresponds to sector two,
and the last byte of data corresponding to sector three.
After the last data byte has been clocked in, the CS pin must be deasserted to initiate the internally self-timed
program cycle. The programming of the Sector Protection Register should take place in a time of tP, during which
time the Status Register will indicate that the device is busy. If the device is powered-down during the program
cycle, then the contents of the Sector Protection Register cannot be guaranteed.
If the proper number of data bytes is not clocked in before the CS pin is deasserted, then the protection status of
the sectors corresponding to the bytes not clocked in can not be guaranteed. For example, if only the first two bytes
are clocked in instead of the complete 8-bytes, then the protection status of the last six sectors cannot be
Command Byte 1 Byte 2 Byte 3 Byte 4
Erase Sector Protection Register 3DH 2AH 7FH CFH
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Each transition
represents 8 bits
SI
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guaranteed. Furthermore, if more than 8-bytes of data is clocked into the device, then the data will wrap back
around to the beginning of the register. For instance, if 9-bytes of data are clocked in, then the ninth byte will be
stored at byte location zero of the Sector Protection Register.
If a value other than 00H or FFH is clocked into a byte location of the Sector Protection Register, then the
protection status of the sector corresponding to that byte location cannot be guaranteed. For example, if a value of
17H is clocked into byte location two of the Sector Protection Register, then the protection status of sector two
cannot be guaranteed.
The Sector Protection Register can be reprogrammed while the sector protection enabled or disabled. Being able
to reprogram the Sector Protection Register with the sector protection enabled allows the user to temporarily
disable the sector protection to an individual sector rather than disabling sector protection completely.
The Program Sector Protection Register command utilizes the internal SRAM buffer for processing. Therefore, the
contents of the buffer will be altered from its previous state when this command is issued.
Table 7-5. Program Sector Protection Register Command
Figure 7-3. Program Sector Protection Register
7.1.3 Read Sector Protection Register Command
To read the Sector Protection Register, the CS pin must first be asserted. Once the CS pin has been asserted, an
opcode of 32H and three dummy bytes must be clocked in via the SI pin. After the last bit of the opcode and
dummy bytes have been clocked in, any additional clock pulses on the SCK pins will result in data for the content
of the Sector Protection Register being output on the SO pin. The first byte corresponds to sector 0 (0a, 0b), the
second byte corresponds to sector one, the third byte corresponds to sector two, and the last byte (byte four)
corresponds to sector three. Once the last byte of the Sector Protection Register has been clocked out, any
additional clock pulses will result in undefined data being output on the SO pin. The CS must be deasserted to
terminate the Read Sector Protection Register operation and put the output into a high-impedance state.
Table 7-6. Read Sector Protection Register Command
Note: xx = Dummy Byte
Figure 7-4. Read Sector Protection Register
Command Byte 1 Byte 2 Byte 3 Byte 4
Program Sector Protection Register 3DH 2AH 7FH FCH
Data Byte
n
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
Data Byte
n + 1
Data Byte
n + 7
CS
Each transition
represents 8 bits
SI
Command Byte 1 Byte 2 Byte 3 Byte 4
Read Sector Protection Register 32H xxH xxH xxH
Opcode X X X
Data Byte
n
Data Byte
n + 1
CS
Data Byte
n + 7
SI
SO
Each transition
represents 8 bits
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7.1.4 Various Aspects About the Sector Protection Register
The Sector Protection Register is subject to a limit of 10,000 erase/program cycles. Users are encouraged to
carefully evaluate the number of times the Sector Protection Register will be modified during the course of the
applications’ life cycle. If the application requires that the Sector Protection Register be modified more than the
specified limit of 10,000 cycles because the application needs to temporarily unprotect individual sectors (sector
protection remains enabled while the Sector Protection Register is reprogrammed), then the application will need
to limit this practice. Instead, a combination of temporarily unprotecting individual sectors along with disabling
sector protection completely will need to be implemented by the application to ensure that the limit of 10,000 cycles
is not exceeded.
8. Security Features
8.1 Sector Lockdown
The device incorporates a Sector Lockdown mechanism that allows each individual sector to be permanently
locked so that it becomes read only. This is useful for applications that require the ability to permanently protect a
number of sectors against malicious attempts at altering program code or security information. Once a sector is
locked down, it can never be erased or programmed, and it can never be unlocked.
To issue the Sector Lockdown command, the CS pin must first be asserted as it would be for any other command.
Once the CS pin has been asserted, the appropriate 4-byte opcode sequence must be clocked into the device in
the correct order. The 4-byte opcode sequence must start with 3DH and be followed by 2AH, 7FH, and 30H. After
the last byte of the command sequence has been clocked in, then three address bytes specifying any address
within the sector to be locked down must be clocked into the device. After the last address bit has been clocked in,
the CS pin must then be deasserted to initiate the internally self-timed lockdown sequence.
The lockdown sequence should take place in a maximum time of tP, during which time the Status Register will
indicate that the device is busy. If the device is powered-down before the completion of the lockdown sequence,
then the lockdown status of the sector cannot be guaranteed. In this case, it is recommended that the user read the
Sector Lockdown Register to determine the status of the appropriate sector lockdown bits or bytes and reissue the
Sector Lockdown command if necessary.
Table 8-1. Sector Lockdown
Figure 8-1. Sector Lockdown
Command Byte 1 Byte 2 Byte 3 Byte 4
Sector Lockdown 3DH 2AH 7FH 30H
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Address
Bytes
Address
Bytes
Address
Bytes
Each transition
represents 8 bits
SI
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8.1.1 Sector Lockdown Register
Sector Lockdown Register is a nonvolatile register that contains 8-bytes of data, as shown below:
Table 8-2. Sector Lockdown Register
Table 8-3. Sector 0 (0a, 0b)
8.1.2 Reading the Sector Lockdown Register
The Sector Lockdown Register can be read to determine which sectors in the memory array are permanently
locked down. To read the Sector Lockdown Register, the CS pin must first be asserted. Once the CS pin has been
asserted, an opcode of 35H and 3 dummy bytes must be clocked into the device via the SI pin. After the last bit of
the opcode and dummy bytes have been clocked in, the data for the contents of the Sector Lockdown Register will
be clocked out on the SO pin. The first byte corresponds to sector 0 (0a, 0b) the second byte corresponds to sector
one and the last byte (byte eight) corresponds to sector seven. After the last byte of the Sector Lockdown Register
has been read, additional pulses on the SCK pin will simply result in undefined data being output on the SO pin.
Deasserting the CS pin will terminate the Read Sector Lockdown Register operation and put the SO pin into a
high-impedance state.
Table 8-4 details the values read from the Sector Lockdown Register.
Table 8-4. Sector Lockdown Register
Figure 8-2. Read Sector Lockdown Register
Sector Number 0 (0a, 0b) 1 to 7
Locked See Below FFH
Unlocked 00H
0a 0b
Bit 3, 2
Data
Value
(Page 0-7) (Page 8-127)
Bit 7, 6 Bit 5, 4 Bit 1, 0
Sectors 0a, 0b Unlocked 00 00 00 00 00H
Sector 0a Locked (Page 0-7) 11 00 00 00 C0H
Sector 0b Locked (Page 8-127) 00 11 00 00 30H
Sectors 0a, 0b Locked (Page 0-127) 11 11 00 00 F0H
Command Byte 1 Byte 2 Byte 3 Byte 4
Read Sector Lockdown Register 35H xxH xxH xxH
Note: xx = Dummy Byte
Opcode X X X
Data Byte
n
Data Byte
n + 1
CS
Data Byte
n + 7
SI
SO
Each transition
represents 8 bits
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8.2 Security Register
The device contains a specialized Security Register that can be used for purposes such as unique device
serialization or locked key storage. The register is comprised of a total of 128-bytes that is divided into two
portions. The first 64-bytes (byte locations 0 through 63) of the Security Register are allocated as a one-time user
programmable space. Once these 64-bytes have been programmed, they cannot be reprogrammed. The
remaining 64-bytes of the register (byte locations 64 through 127) are factory programmed by Adesto and will
contain a unique value for each device. The factory programmed data is fixed and cannot be changed.
Table 8-5. Security Register
8.2.1 Programming the Security Register
The user programmable portion of the Security Register does not need to be erased before it is programmed.
To program the Security Register, the CS pin must first be asserted and the appropriate 4-byte opcode sequence
must be clocked into the device in the correct order. The 4-byte opcode sequence must start with 9BH and be
followed by 00H, 00H, and 00H. After the last bit of the opcode sequence has been clocked into the device, the
data for the contents of the 64-byte user programmable portion of the Security Register must be clocked in.
After the last data byte has been clocked in, the CS pin must be deasserted to initiate the internally self-timed
program cycle. The programming of the Security Register should take place in a time of tP, during which time the
Status Register will indicate that the device is busy. If the device is powered-down during the program cycle, then
the contents of the 64-byte user programmable portion of the Security Register cannot be guaranteed.
If the full 64-bytes of data is not clocked in before the CS pin is deasserted, then the values of the byte locations
not clocked in cannot be guaranteed. For example, if only the first two bytes are clocked in instead of the complete
64 bytes, then the remaining 62-bytes of the user programmable portion of the Security Register cannot be
guaranteed. Furthermore, if more than 64-bytes of data is clocked into the device, then the data will wrap back
around to the beginning of the register. For instance, if 65-bytes of data are clocked in, then the 65th byte will be
stored at byte location 0 of the Security Register.
The user programmable portion of the Security Register can only be programmed one time. Therefore, it is
not possible to only program the first two bytes of the register and then program the remaining 62-bytes at a later
time.
The Program Security Register command utilizes the internal SRAM buffer for processing. Therefore, the contents
of the buffer will be altered from its previous state when this command is issued.
Figure 8-3. Program Security Register
Security Register Byte Number
0 1 · · · 62 63 64 65 · · · 126 127
Data Type One-time User Programmable Factory Programmed By Adesto
Data Byte
n
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
Data Byte
n + 1
Data Byte
n + 63
CS
Each transition
represents 8 bits
SI
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8.2.2 Reading the Security Register
The Security Register can be read by first asserting the CS pin and then clocking in an opcode of 77H followed by
three dummy bytes. After the last don’t care bit has been clocked in, the content of the Security Register can be
clocked out on the SO pins. After the last byte of the Security Register has been read, additional pulses on the
SCK pin will simply result in undefined data being output on the SO pins.
Deasserting the CS pin will terminate the Read Security Register operation and put the SO pins into a high-
impedance state.
Figure 8-4. Read Security Register
9. Additional Commands
9.1 Main Memory Page to Buffer Transfer
A page of data can be transferred from the main memory to the buffer. To start the operation for the DataFlash
standard page size (264-bytes), a 1-byte opcode, 53H, must be clocked into the device, followed by three address
bytes comprised of five don’t care bits, 10 page address bits (PA9 - PA0), which specify the page in main memory
that is to be transferred, and 9 don’t care bits. To perform a main memory page to buffer transfer for the binary
page size (256-bytes), the opcode 53H must be clocked into the device followed by three address bytes consisting
of six don’t care bits, 10 page address bits (A17 - A8) which specify the page in the main memory that is to be
transferred, and eight don’t care bits. The CS pin must be low while toggling the SCK pin to load the opcode and
the address bytes from the input pin (SI). The transfer of the page of data from the main memory to the buffer will
begin when the CS pin transitions from a low to a high state. During the transfer of a page of data (tXFR), the status
register can be monitored to determine whether the transfer has been completed.
9.2 Main Memory Page to Buffer Compare
A page of data in main memory can be compared to the data in the buffer. To initiate the operation for the
DataFlash standard page size, a 1-byte opcode, 60H, must be clocked into the device, followed by three address
bytes consisting of five don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory
that is to be compared to the buffer, and nine don’t care bits. To start a main memory page to buffer compare for a
binary page size, the opcode 60H must be clocked into the device followed by three address bytes consisting of six
don’t care bits, ten page address bits (A17 - A8) that specify the page in the main memory that is to be compared
to the buffer, and eight don’t care bits. The CS pin must be low while toggling the SCK pin to load the opcode and
the address bytes from the input pin (SI). On the low-to-high transition of the CS pin, the data bytes in the selected
main memory page will be compared with the data bytes in the buffer. During this time (tCOMP), the status register
will indicate that the part is busy. On completion of the compare operation, bit 6 of the status register is updated
with the result of the compare.
9.3 Auto Page Rewrite
This mode is only needed if multiple bytes within a page or multiple pages of data are modified in a random fashion
within a sector. This mode is a combination of two operations: Main Memory Page to Buffer Transfer and Buffer to
Opcode X X X
Data Byte
n
Data Byte
n + 1
CS
Data Byte
n + x
Each transition
represents 8 bits
SI
SO
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Main Memory Page Program with Built-in Erase. A page of data is first transferred from the main memory to the
buffer and then the same data (from the buffer) is programmed back into its original page of main memory. To start
the rewrite operation for the DataFlash standard page size (264-bytes), a 1-byte opcode, 58H, must be clocked into
the device, followed by three address bytes comprised of five don’t care bits, 10 page address bits (PA9-PA0) that
specify the page in main memory to be rewritten and nine don’t care bits. To initiate an auto page rewrite for a
binary page size (256-bytes), the opcode 58H must be clocked into the device followed by three address bytes
consisting of six don’t care bits, 10 page address bits (A17 - A8) that specify the page in the main memory that is to
be written and eight don’t care bits. When a low-to-high transition occurs on the CS pin, the part will first transfer
data from the page in main memory to a buffer and then program the data from the buffer back into same page of
main memory. The operation is internally self-timed and should take place in a maximum time of tEP. During this
time, the status register indicate that the part is busy.
If a sector is programmed or reprogrammed sequentially page by page, then the programming algorithm shown in
Figure 20-1 (page 41) is recommended. Otherwise, if multiple bytes in a page or several pages are programmed
randomly in a sector, then the programming algorithm shown in Figure 20-2 (page 42) is recommended. Each
page within a sector must be updated/rewritten at least once within every 20,000 cumulative page erase/program
operations in that sector. Please contact Adesto for availability of devices that are specified to exceed the 20K
cycle cumulative limit.
9.4 Status Register Read
The status register can be used to determine the device’s ready/busy status, page size, a Main Memory Page to
Buffer Compare operation result, the Sector Protection status or the device density. The Status Register can be
read at any time, including during an internally self-timed program or erase operation. To read the status register,
the CS pin must be asserted and the opcode of D7H must be loaded into the device. After the opcode is clocked in,
the 1-byte status register will be clocked out on the output pin (SO), starting with the next clock cycle. The data in
the status register, starting with the MSB (bit seven), will be clocked out on the SO pin during the next eight clock
cycles. After the one byte of the status register has been clocked out, the sequence will repeat itself (as long as CS
remains low and SCK is being toggled). The data in the status register is constantly updated, so each repeating
sequence will output new data.
Ready/busy status is indicated using bit seven of the status register. If bit seven is a one, then the device is not
busy and is ready to accept the next command. If bit seven is a zero, then the device is in a busy state. Since the
data in the status register is constantly updated, the user must toggle SCK pin to check the ready/busy status.
There are several operations that can cause the device to be in a busy state: Main Memory Page to Buffer
Transfer, Main Memory Page to Buffer Compare, Buffer to Main Memory Page Program, Main Memory Page
Program through Buffer, Page Erase, Block Erase, Sector Erase, Chip Erase and Auto Page Rewrite.
The result of the most recent Main Memory Page to Buffer Compare operation is indicated using bit six of the
status register. If bit six is a zero, then the data in the main memory page matches the data in the buffer. If bit six is
a one, then at least one bit of the data in the main memory page does not match the data in the buffer.
Bit one in the Status Register is used to provide information to the user whether or not the sector protection has
been enabled or disabled, either by software-controlled method or hardware-controlled method. A logic 1 indicates
that sector protection has been enabled and logic 0 indicates that sector protection has been disabled.
Bit zero in the Status Register indicates whether the page size of the main memory array is configured for “power
of 2” binary page size (256-bytes) or the DataFlash standard page size (264-bytes). If bit zero is a one, then the
page size is set to 256-bytes. If bit zero is a zero, then the page size is set to 264-bytes.
The device density is indicated using bits five, four, three, and two of the status register. For AT45DB021D, the four
bits are 0101 The decimal value of these four binary bits does not equate to the device density; the four bits
represent a combinational code relating to differing densities of DataFlash devices. The device density is not the
same as the density code indicated in the JEDEC device ID information. The device density is provided only for
backward compatibility.
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Table 9-1. Status Register Format
10. Deep Power-down
After initial power-up, the device will default in standby mode. The Deep Power-down command allows the device
to enter into the lowest power consumption mode. To enter the Deep Power-down mode, the CS pin must first be
asserted. Once the CS pin has been asserted, an opcode of B9H command must be clocked in via input pin (SI).
After the last bit of the command has been clocked in, the CS pin must be de-asserted to initiate the Deep Power-
down operation. After the CS pin is de-asserted, the will device enter the Deep Power-down mode within the
maximum tEDPD time. Once the device has entered the Deep Power-down mode, all instructions are ignored except
for the Resume from Deep Power-down command.
Table 10-1. Deep Power-down
Figure 10-1. Deep Power-down
10.1 Resume from Deep Power-down
The Resume from Deep Power-down command takes the device out of the Deep Power-down mode and returns it
to the normal standby mode. To Resume from Deep Power-down mode, the CS pin must first be asserted and an
opcode of ABH command must be clocked in via input pin (SI). After the last bit of the command has been clocked
in, the CS pin must be de-asserted to terminate the Deep Power-down mode. After the CS pin is de-asserted, the
device will return to the normal standby mode within the maximum tRDPD time. The CS pin must remain high during
the tRDPD time before the device can receive any commands. After resuming form Deep Power-down, the device
will return to the normal standby mode.
Table 10-2. Resume from Deep Power-down
Figure 10-2. Resume from Deep Power-Down
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
RDY/BUSY COMP 0 1 0 1 PROTECT PAGE SIZE
Command Opcode
Deep Power-down B9H
Opcode
CS
Each transition
represents 8 bits
SI
Command Opcode
Resume from Deep Power-down ABH
Opcode
CS
Each transition
represents 8 bits
SI
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11. “Power of 2” Binary Page Size Option
“Power of 2” binary page size Configuration Register is a user-programmable nonvolatile register that allows the
page size of the main memory to be configured for binary page size (256-bytes) or the DataFlash standard page
size (264-bytes). The “power of 2” page size is a One-time Programmable (OTP) register and once the
device is configured for “power of 2” page size, it cannot be reconfigured again. The devices are initially
shipped with the page size set to 264-bytes. The user has the option of ordering binary page size (256-bytes)
devices from the factory. For details, please refer to Section 21. “Ordering Information” on page 43.
For the binary “power of 2” page size to become effective, the following steps must be followed:
1. Program the one-time programmable configuration resister using opcode sequence 3DH, 2AH, 80H and
A6H (please see Section 11.1).
2. Power cycle the device (i.e. power down and power up again).
3. The page for the binary page size can now be programmed.
If the above steps are not followed to set the page size prior to page programming, incorrect data during a read
operation may be encountered.
11.1 Programming the Configuration Register
To program the Configuration Register for “power of 2” binary page size, the CS pin must first be asserted as it
would be with any other command. Once the CS pin has been asserted, the appropriate 4-byte opcode sequence
must be clocked into the device in the correct order. The 4-byte opcode sequence must start with 3DH and be
followed by 2AH, 80H, and A6H. After the last bit of the opcode sequence has been clocked in, the CS pin must be
deasserted to initiate the internally self-timed program cycle. The programming of the Configuration Register
should take place in a time of tP, during which time the Status Register will indicate that the device is busy. The
device must be power-cycled after the completion of the program cycle to set the “power of 2” page size. If the
device is powered-down before the completion of the program cycle, then setting the Configuration Register
cannot be guaranteed. However, the user should check bit zero of the status register to see whether the page size
was configured for binary page size. If not, the command can be re-issued again.
Table 11-1. Programming the Configuration Register
Figure 11-1. Erase Sector Protection Register
12. Manufacturer and Device ID Read
Identification information can be read from the device to enable systems to electronically query and identify the
device while it is in system. The identification method and the command opcode comply with the JEDEC standard
for “Manufacturer and Device ID Read Methodology for SPI Compatible Serial Interface Memory Devices”. The
type of information that can be read from the device includes the JEDEC defined Manufacturer ID, the vendor
specific Device ID, and the vendor specific Extended Device Information.
To read the identification information, the CS pin must first be asserted and the opcode of 9FH must be clocked
into the device. After the opcode has been clocked in, the device will begin outputting the identification data on the
SO pin during the subsequent clock cycles. The first byte that will be output will be the Manufacturer ID followed by
Command Byte 1 Byte 2 Byte 3 Byte 4
Power of Two Page Size 3DH 2AH 80H A6H
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Each transition
represents 8 bits
SI
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3638M–DFLASH–5/2013
AT45DB021D
two bytes of Device ID information. The fourth byte output will be the Extended Device Information String Length,
which will be 00H indicating that no Extended Device Information follows. As indicated in the JEDEC standard,
reading the Extended Device Information String Length and any subsequent data is optional.
Deasserting the CS pin will terminate the Manufacturer and Device ID Read operation and put the SO pin into a
high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be
read.
12.1 Manufacturer and Device ID Information
Table 12-1. Byte 1 – Manufacturer ID
Table 12-2. Byte 2 – Device ID (Part 1)
Table 12-3. Byte 3 – Device ID (Part 2)
Table 12-4. Byte 4 – Extended Device Information String Length
Note: Based on JEDEC publication 106 (JEP106), Manufacturer ID data can be comprised of any number of bytes. Some
manufacturers may have Manufacturer ID codes that are two, three or even four bytes long with the first byte(s) in the
sequence being 7FH. A system should detect code 7FH as a “Continuation Code” and continue to read Manufacturer
ID bytes. The first non-7FH byte would signify the last byte of Manufacturer ID data. For Adesto (and some other man-
ufacturers), the Manufacturer ID data is comprised of only one byte.
Hex
Value
JEDEC Assigned Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1FH 0 0 0 1 1 1 1 1 Manufacturer ID 1FH = Adesto
Hex
Value
Family Code Density Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Family Code 001 = DataFlash
23H 0 0 1 0 0 0 1 1 Density Code 00011 = 2-Mbit
Hex
Value
MLC Code Product Version Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MLC Code 000 = 1-bit/Cell
Technology
00H 0 0 0 0 0 0 0 0 Product Version 00000 = Initial Version
Hex
Value
Byte Count
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
00H 0 0 0 0 0 0 0 0 Byte Count 00H = 0 Bytes of Information
9FH
Manufacturer ID
Byte n
Device ID
Byte 1
Device ID
Byte 2
This information would only be output
if the Extended Device Information String Length
value was something other than 00H.
Extended
Device
Information
String Length
Extended
Device
Information
Byte x
Extended
Device
Information
Byte x + 1
CS
1FH 23H 00H 00H Data Data
SI
SO
Opcode
Each transition
represents 8 bits
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AT45DB021D
12.2 Operation Mode Summary
The commands described previously can be grouped into four different categories to better describe which
commands can be executed at what times.
Group A commands consist of:
1. Main Memory Page Read
2. Continuous Array Read
3. Read Sector Protection Register
4. Read Sector Lockdown Register
5. Read Security Register
Group B commands consist of:
1. Page Erase
2. Block Erase
3. Sector Erase
4. Chip Erase
5. Main Memory Page to Buffer Transfer
6. Main Memory Page to Buffer Compare
7. Buffer to Main Memory Page Program with Built-in Erase
8. Buffer to Main Memory Page Program without Built-in Erase
9. Main Memory Page Program through Buffer
10. Auto Page Rewrite
Group C commands consist of:
1. Buffer Read
2. Buffer Write
3. Status Register Read
4. Manufacturer and Device ID Read
Group D commands consist of:
1. Erase Sector Protection Register
2. Program Sector Protection Register
3. Sector Lockdown
4. Program Security Register
If a Group A command is in progress (not fully completed), then another command in Group A, B, C, or D should
not be started. However, during the internally self-timed portion of Group B commands one through four, any
command in Group C can be executed. During the internally self-timed portion of Group B commands five through
ten, only Group C commands three and four can be executed. Finally, during the internally self-timed portion of a
Group D command, only the Status Register Read command should be executed.
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13. Command Tables
Table 13-1. Read Commands
Table 13-2. Program and Erase Commands
Table 13-3. Protection and Security Commands
Command Opcode
Main Memory Page Read D2H
Continuous Array Read (Legacy Command) E8H
Continuous Array Read (Low Frequency) 03H
Continuous Array Read (High Frequency) 0BH
Buffer Read (Low Frequency) D1H
Buffer Read D4H
Command Opcode
Buffer Write 84H
Buffer to Main Memory Page Program with Built-in Erase 83H
Buffer to Main Memory Page Program without Built-in Erase 88H
Page Erase 81H
Block Erase 50H
Sector Erase 7CH
Chip Erase 7CH, 94H, 80H, 9AH
Main Memory Page Program through Buffer 82H
Command Opcode
Enable Sector Protection 3DH + 2AH + 7FH + A9H
Disable Sector Protection 3DH + 2AH + 7FH + 9AH
Erase Sector Protection Register 3DH + 2AH + 7FH + CFH
Program Sector Protection Register 3DH + 2AH + 7FH + FCH
Read Sector Protection Register 32H
Sector Lockdown 3DH + 2AH + 7FH + 30H
Read Sector Lockdown Register 35H
Program Security Register 9BH + 00H + 00H + 00H
Read Security Register 77H
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AT45DB021D
Table 13-4. Additional Commands
Table 13-5. Legacy Commands(1)
Note: 1. These legacy commands are not recommended for new designs
Command Opcode
Main Memory Page to Buffer Transfer 53H
Main Memory Page to Buffer Compare 60H
Auto Page Rewrite through Buffer 58H
Deep Power-down B9H
Resume from Deep Power-down ABH
Status Register Read D7H
Manufacturer and Device ID Read 9FH
Command Opcode
Buffer Read 54H
Main Memory Page Read 52H
Continuous Array Read 68H
Status Register Read 57H
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Table 13-6. Detailed Bit-level Addressing Sequence for Binary Page Size (256-Bytes)
Note: x = Don’t Care
Page Size = 256-bytes Address Byte Address Byte Address Byte
Additional
Don’t Care
Bytes
Opco
de Opcode
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
A17
A16
A15
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
03h 0 0 0 0 0 0 1 1 x x x x x x AA AAAAAAAA AAAAAAAA N/A
0Bh 0 0 0 0 1 0 1 1 x x x x x x AA AAAAAAAA AAAAAAAA 1
50h 01010000 xxxxxxAAAAAAAxxx xxxxxxxx N/A
53h 01010011 xxxxxxAAAAAAAAAA xxxxxxx x N/A
58h 01011000 xxxxxxAAAAAAAAAA xxxxxxx x N/A
60h 01100000 xxxxxxAAAAAAAAAA xxxxxxx x N/A
77h 01110111 xxxxxxxx xxxxxxxx xxxxxxxx N/A
7Ch 01111100 xxxxxxAx xxxxxxxx xxxxxxxx N/A
81h 10000001 xxxxxxAAAAAAAAAA xxxxxxx x N/A
82h 1 0 0 0 0 0 1 0 x x x x x x AA AAAAAAAA AAAAAAAA N/A
83h 10000011 xxxxxxAAAAAAAAAA xxxxxxx x N/A
84h 10000100 xxxxxxxx xxxxxxxx AAAAAAAA N/A
88h 10001000 xxxxxxAAAAAAAAAA xxxxxxx x N/A
9Fh 1 0 0 1 1 1 1 1 N/A N/A N/A N/A
B9h 1 0 1 1 1 0 0 1 N/A N/A N/A N/A
ABh 1 0 1 0 1 0 1 1 N/A N/A N/A N/A
D1h 11010001 xxxxxxxx xxxxxxxx AAAAAAAA N/A
D2h 1 1 0 1 0 0 1 0 x x x x x x AA AAAAAAAA AAAAAAAA 4
D4h 11010100 xxxxxxxx xxxxxxxx AAAAAAAA 1
D7h 1 1 0 1 0 1 1 1 N/A N/A N/A N/A
E8h 1 1 1 0 1 0 0 0 x x x x x x AA AAAAAAAA AAAAAAAA 4
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Table 13-7. Detailed Bit-level Addressing Sequence for Standard DataFlash Page Size (264-Bytes)
Note: P = Page Address Bit
B = Byte/Buffer Address Bit
x = Don’t Care
Page Size = 264-bytes Address Byte Address Byte Address Byte
Additional
Don’t Care
BytesOpcode Opcode
Reserved
Reserved
Reserved
Reserved
Reserved
PA9
PA8
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
BA8
BA7
BA6
BA5
BA4
BA3
BA2
BA1
BA0
03h 00000011 xxxxxPPP PPPPPPPB BBBBBBBB N/A
0Bh 00001011 xxxxxPPP PPPPPPPB BBBBBBBB 1
50h 01010000 xxxxxPPP PPPPx x x x x x x x x x x x N/A
53h 01010011 xxxxxPPP PPPPPPPx x x x x x x x x N/A
58h 01011000 xxxxxPPP PPPPPPPx x x x x x x x x N/A
60h 01100000 xxxxxPPP PPPPPPPx x x x x x x x x N/A
77h 01110111 xxxxxxxx xxxxxxxx xxxxxxx x N/A
7Ch 01111100 xxxxxPxx xxxxxxxx xxxxxxx x N/A
81h 10000001 xxxxxPPP PPPPPPPx x x x x x x x x N/A
82h 10000010 xxxxxPPP PPPPPPPB BBBBBBBB N/A
83h 10000011 xxxxxPPP PPPPPPPx x x x x x x x x N/A
84h 10000100 xxxxxxxx xxxxxxxB BBBBBBBB N/A
88h 10001000 xxxxxPPP PPPPPPPx x x x x x x x x N/A
9Fh 10011111 N/A N/A N/A N/A
B9h 10111001 N/A N/A N/A N/A
ABh 10101011 N/A N/A N/A N/A
D1h 11010001 xxxxxxxx xxxxxxxB BBBBBBBB N/A
D2h 11010010 xxxxxPPP PPPPPPPB BBBBBBBB 4
D4h 11010100 xxxxxxxx xxxxxxxB BBBBBBBB 1
D7h 11010111 N/A N/A N/A N/A
E8h 11101000 xxxxxPPP PPPPPPPB BBBBBBBB 4
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14. Power-on/Reset State
When power is first applied to the device, or when recovering from a reset condition, the device will default to Mode
3. In addition, the output pin (SO) will be in a high impedance state, and a high-to-low transition on the CS pin will
be required to start a valid instruction. The mode (Mode 3 or Mode 0) will be automatically selected on every falling
edge of CS by sampling the inactive clock state.
14.1 Initial Power-up/Reset Timing Restrictions
At power up, the device must not be selected until the supply voltage reaches the VCC (min.) and further delay of
tVCSL. During power-up, the internal Power-on Reset circuitry keeps the device in reset mode until the VCC rises
above the Power-on Reset threshold value (VPOR). At this time, all operations are disabled and the device does not
respond to any commands. After power up is applied and the VCC is at the minimum operating voltage VCC (min.),
the tVCSL delay is required before the device can be selected in order to perform a read operation.
Similarly, the tPUW delay is required after the VCC rises above the Power-on Reset threshold value (VPOR) before the
device can perform a write (Program or Erase) operation. After initial power-up, the device will default in Standby
mode.
Table 14-1. Initial Power-up/Reset Timing Restrictions
15. System Considerations
The serial interface is controlled by the clock SCK, serial input SI and chip select CS pins. These signals must rise
and fall monotonically and be free from noise. Excessive noise or ringing on these pins can be misinterpreted as
multiple edges and cause improper operation of the device. The PC board traces must be kept to a minimum
distance or appropriately terminated to ensure proper operation. If necessary, decoupling capacitors can be added
on these pins to provide filtering against noise glitches.
As system complexity continues to increase, voltage regulation is becoming more important. A key element of any
voltage regulation scheme is its current sourcing capability. Like all Flash memories, the peak current for
DataFlash occur during the programming and erase operation. The regulator needs to supply this peak current
requirement. An under specified regulator can cause current starvation. Besides increasing system noise, current
starvation during programming or erase can lead to improper operation and possible data corruption.
In an effort to continue our goal of maintaining world-class quality leadership, Adesto has been performing
extensive testing on the AT45DB021D that would not normally be done with a Serial Flash device. The testing that
has been performed on the AT45DB021D involved extensive, non-stop reading of the memory array on pre-
conditioned devices. The pre-conditioning of the devices, which entailed erasing and programming the entire
memory array 10,000 times, was done to simulate a customer environment and to exercise the memory cells to a
certain degree. The non-stop reading of the devices was done in three levels of granularity, with the first level
involving a continuous, looped read of 256-bytes (a single page) of memory, the second level involving a
continuous, looped-read of a 4-Kbyte (16-pages) portion of memory, and the third level entailing non-stop reading
of the entire memory array. Read operations were performed at both +25°C and +125°C and with a supply voltage
of 3.7V, which exceeds the specified datasheet operating voltage range. The results of all of the extensive tests
indicate that the contents of a portion of memory being read continuously could be altered after 800,000,000 read
operations only if that portion of the memory was not erased or reprogrammed at all during the 800,000,000 read
operations. If that portion of memory was reprogrammed at some point, then it would take another 800,000,000
Symbol Parameter Min Typ Max Units
tVCSL VCC (min.) to Chip Select low 1 ms
tPUW Power-Up Device Delay before Write Allowed 20 ms
VPOR Power-On Reset Voltage 1.5 2.5 V
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3638M–DFLASH–5/2013
AT45DB021D
read operations after reprogramming before the contents could potentially be altered. For example, if the Serial
Flash is being used for boot code storage, then it would take 800,000,000 boot operations before that boot code
may become altered, provided that the boot code was not updated or reprogrammed. If an application was to read
the entire memory array non-stop at a clock frequency of 10MHz, it would take over five years to reach
800,000,000 read operations. Adesto firmly believes that this extended testing result should not be a cause for
concern. We also believe that most, if not all, applications will never read the same portion of memory 800,000,000
times throughout the life of the application without ever updating that portion of memory.
16. Electrical Specifications
Table 16-1. DC and AC Operating Range
Temperature under Bias..................-55°C to +125°C *NOTICE: Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. The "Absolute Maximum Rat-
ings" are stress ratings only and functional
operation of the device at these or any other con-
ditions beyond those indicated in the operational
sections of this specification is not implied. Expo-
sure to absolute maximum rating conditions for
extended periods may affect device reliability.
Voltage Extremes referenced in the "Absolute
Maximum Ratings" are intended to accommodate
short duration undershoot/overshoot conditions
and does not imply or guarantee functional
device operation at these levels for any extended
period of time
Storage Temperature ......................-65°C to +150°C
All Input Voltages (except VCC but including NC
pins))
with Respect to Ground.................... -0.6V to +6.25V
All Output Voltages
with Respect to Ground.............. -0.6V to VCC + 0.6V
AT45DB021D
Operating Temperature (Case) Ind. -40°C to 85°C
VCC Power Supply 2.7V to 3.6V
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AT45DB021D
Table 16-2. DC Characteristics
Notes: 1. ICC1 during a buffer read is 20mA maximum @ 20MHz
2. All inputs (SI, SCK, CS#, WP#, and RESET#) are guaranteed by design to be 5V tolerant
Symbol Parameter Condition Min Typ Max Units
IDP Deep Power-down Current CS, RESET, WP = VIH, all
inputs at CMOS levels 15 25 μA
ISB Standby Current CS, RESET, WP = VIH, all
inputs at CMOS levels 25 50 μA
ICC1(1) Active Current, Read
Operation
f = 20MHz; IOUT = 0mA;
VCC = 3.6V 710mA
f = 33MHz; IOUT = 0mA;
VCC = 3.6V 812mA
f = 50MHz; IOUT = 0mA;
VCC = 3.6V 10 14 mA
f = 66MHz; IOUT = 0mA;
VCC = 3.6V 11 15 mA
ICC2
Active Current, Program/Erase
Operation VCC = 3.6V 12 17 mA
ILI Input Load Current VIN = CMOS levels 1 μA
ILO Output Leakage Current VI/O = CMOS levels 1 μA
VIL Input Low Voltage VCC x 0.3 V
VIH Input High Voltage VCC x 0.7 V
VOL Output Low Voltage IOL = 1.6mA; VCC = 2.7V 0.4 V
VOH Output High Voltage IOH = -100μAV
CC - 0.2V V
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AT45DB021D
Table 16-3. AC Characteristics – RapidS/Serial Interface
Figure 16-1. Input Test Waveforms and Measurement Levels
tR, tF < 2ns (10% to 90%)
Symbol Parameter Min Typ Max Units
fSCK SCK Frequency 66 MHz
fCAR1 SCK Frequency for Continuous Array Read 66 MHz
fCAR2 SCK Frequency for Continuous Array Read (Low Frequency) 33 MHz
tWH SCK High Time 6.8 ns
tWL SCK Low Time 6.8 ns
tSCKR(1) SCK Rise Time, Peak-to-Peak (Slew Rate) 0.1 V/ns
tSCKF(1) SCK Fall Time, Peak-to-Peak (Slew Rate) 0.1 V/ns
tCS Minimum CS High Time 50 ns
tCSS CS Setup Time 5 ns
tCSH CS Hold Time 5 ns
tSU Data In Setup Time 2 ns
tHData In Hold Time 3 ns
tHO Output Hold Time 0 ns
tDIS Output Disable Time 27 35 ns
tVOutput Valid 6ns
tWPE WP Low to Protection Enabled 1 μs
tWPD WP High to Protection Disabled 1 μs
tEDPD CS High to Deep Power-down Mode 3 μs
tRDPD CS High to Standby Mode 35 μs
tXFR Page to Buffer Transfer Time 200 μs
tcomp Page to Buffer Compare Time 200 μs
tEP Page Erase and Programming Time (256-/264-bytes) 14 35 ms
tPPage Programming Time (256-/264-bytes) 2 4 ms
tPE Page Erase Time (256-/264-bytes) 13 32 ms
tBE Block Erase Time (2,048-2,112-bytes) 15 35 ms
tSE Sector Erase Time (32,768-/33,792-bytes) 400 700 ms
tCE Chip Erase Time 3.6 6 s
tRST RESET Pulse Width 10 μs
tREC RESET Recovery Time 1 μs
AC
DRIVING
LEVELS
AC
MEASUREMENT
LEVEL
0.45V
1.5V
2.4V
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3638M–DFLASH–5/2013
AT45DB021D
Figure 16-2. Output Test Load
17. AC Waveforms
Six different timing waveforms are shown on page 32. Waveform 1 shows the SCK signal being low when CS
makes a high-to-low transition, and waveform 2 shows the SCK signal being high when CS makes a high-to-low
transition. In both cases, output SO becomes valid while the SCK signal is still low (SCK low time is specified as
tWL). Timing waveforms 1 and 2 conform to RapidS serial interface but for frequencies up to 66MHz. Waveforms 1
and 2 are compatible with SPI Mode 0 and SPI Mode 3, respectively.
Waveform 3 and waveform 4 illustrate general timing diagram for RapidS serial interface. These are similar to
waveform 1 and waveform 2, except that output SO is not restricted to become valid during the tWL period. These
timing waveforms are valid over the full frequency range (maximum frequency = 66MHz) of the RapidS serial case.
Figure 17-1. Waveform 1 – SPI Mode 0 Compatible (for Frequencies up to 66MHz)
Figure 17-2. Waveform 2 – SPI Mode 3 Compatible (for Frequencies up to 66MHz)
DEVICE
UNDER
TEST
30pF
CS
SCK
SI
SO
t
CSS
VALID IN
t
H
t
SU
t
WH
t
WL
t
CSH
t
CS
t
V
HIGH IMPEDANCE VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE
CS
SCK
SO
t
CSS
VALID IN
t
H
t
SU
t
WL
t
WH
t
CSH
t
CS
t
V
HIGH Z VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE
SI
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Figure 17-3. Waveform 3 – RapidS Mode 0 (FMAX = 66MHz)
Figure 17-4. Waveform 4 – RapidS Mode 3 (FMAX = 66MHz)
17.1 Utilizing the RapidS Function
To take advantage of the RapidS function's ability to operate at higher clock frequencies, a full clock cycle must be
used to transmit data back and forth across the serial bus. The DataFlash is designed to always clock its data out
on the falling edge of the SCK signal and clock data in on the rising edge of SCK.
For full clock cycle operation to be achieved, when the DataFlash is clocking data out on the falling edge of SCK,
the host controller should wait until the next falling edge of SCK to latch the data in. Similarly, the host controller
should clock its data out on the rising edge of SCK in order to give the DataFlash a full clock cycle to latch the
incoming data in on the next rising edge of SCK.
CS
SCK
SI
SO
t
CSS
VALID IN
t
H
t
SU
t
WH
t
WL
t
CSH
t
CS
t
V
HIGH IMPEDANCE VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE
CS
SCK
SO
t
CSS
VALID IN
t
H
t
SU
t
WL
t
WH
t
CSH
t
CS
t
V
HIGH Z VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE
SI
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Figure 17-5. RapidS Mode
Figure 17-6. Reset Timing
Note: The CS signal should be in the high state before the RESET signal is deasserted
Figure 17-7. Command Sequence for Read/Write Operations for Page Size 256-Bytes (Except Status Register
Read, Manufacturer and Device ID Read)
SCK
MOSI
MISO
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
MOSI = Master Out, Slave In
MISO = Master In, Slave Out
The Master is the host controller and the Slave is the DataFlash
The Master always clocks data out on the rising edge of SCK and always clocks data in on the falling edge of SCK.
The Slave always clocks data out on the falling edge of SCK and always clocks data in on the rising edge of SCK.
A. Master clocks out first bit of BYTE-MOSI on the rising edge of SCK
B. Slave clocks in first bit of BYTE-MOSI on the next rising edge of SCK
C. Master clocks out second bit of BYTE-MOSI on the same rising edge of SCK
D. Last bit of BYTE-MOSI is clocked out from the Master
E. Last bit of BYTE-MOSI is clocked into the slave
F. Slave clocks out first bit of BYTE-SO
G. Master clocks in first bit of BYTE-SO
H. Slave clocks out second bit of BYTE-SO
I. Master clocks in last bit of BYTE-SO
A B C D E
F G
1
H
BYTE-MOSI
MSB LSB
BYTE-SO
MSB LSB
Slave
CS
I
CS
SCK
RESET
SO (OUTPUT) HIGH IMPEDANCE HIGH IMPEDANCE
SI (INPUT)
tRST
tREC tCSS
SI (INPUT) CMD 8 bits 8 bits 8 bits
Page Address
(A17 - A8)
X X X X X X X X X X X X X X X X LSB
X X X X X X X X
Byte/Buffer Address
(A7 - A0/BFA7 - BFA0)
MSB
6 Don’t Care
Bits
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Figure 17-8. Command Sequence for Read/Write Operations for Page Size 264-Bytes (Except Status Register
Read, Manufacturer and Device ID Read)
Figure 17-9. Write Operations
The following block diagram and waveforms illustrate the various write sequences available
Figure 17-10. Buffer Write
Page Address
(PA9 - PA0)
Byte/Buffer Address
(BA8 - BA0/BFA8 - BFA0)
SI (INPUT) CMD 8-bits 8-bits 8-bits
X X X X X X X X X X X X LSB
X X X X X X X X
MSB
5 Don’t Care
Bits
X X X X
FLASH MEMORY ARRAY
PAGE (256-/264 BYTES)
BUFFER (256-/264-BYTES)
I/O INTERFACE
SI
BUFFER TO
MAIN MEMORY
PAGE PROGRAM
BUFFER
WRITE
SI (INPUT) CMD
Completes writing into the buffer
CS
X
X···X, BFA8
BFA7-0
nn+1 Last Byte
BINARY PAGE SIZE
16 DON'T CARE + BFA7-BFA0
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Figure 17-11. Buffer to Main Memory Page Program (Data from Buffer Programmed into Flash Page)
18. Read Operations
The following block diagram and waveforms illustrate the various read sequences available.
Figure 18-1. Main Memory Page Read
SI (INPUT) CMD
PA9-7 PA6-0, X
CS
Starts self-timed erase/program operation
XXXX XX
Each transition
represents 8 bits
n = 1st byte read
n+1 = 2nd byte read
BINARY PAGE SIZE
A17-A8 + 8 DON'T CARE BITS
FLASH MEMORY ARRAY
PAGE (256/264 BYTES)
BUFFER (256/264 BYTES)
I/O INTERFACE
MAIN MEMORY
PAGE TO
BUFFER
MAIN MEMORY
PAGE READ
BUFFER
READ
SO
SI (INPUT)
CMD PA 9 - 7 PA6-0, BA8
X
CS
n n+1
SO (OUTPUT)
BA7-0
4 Dummy Bytes
X
ADDRESS FOR BINARY PAGE SIZE
A17-A16 A15-A8 A7-A0
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3638M–DFLASH–5/2013
AT45DB021D
Figure 18-2. Main Memory Page to Buffer Transfer (Data from Flash Page Read into Buffer)
Figure 18-3. Buffer Read
19. Detailed Bit-level Read Waveform – RapidS Serial Interface Mode 0/Mode 3
Figure 19-1. Continuous Array Read (Legacy Opcode E8H)
Starts reading page data into buffer
SI (INPUT)
CMD X
···
X, PA9-7 PA6-0, X
CS
SO (OUTPUT)
XXXX XXXX
BINARY PAGE SIZE
6 DON’T CARE BITS + A17-A8 + 8 DON'T CARE BITS
CMD
CS
n n+1
X
X
1 Dummy Byte
X..X, BFA8 BFA7- 0
BINARY PAGE SIZE
16 DON'T CARE + BFA7-BFA0
Each transition
represents 8 bits
SI (INPUT)
SO (OUTPUT)
S
CK
CS
SI
SO
MSB MSB
2310
11101000
675410119812 63666765646233 3431 3229 30 68 71 727069
OPCODE
AAAA AAAAA
MSB
XXXX XX
MSB MSB
DDDDDDDDDD
ADDRESS BITS 32 DON'T CARE BITS
DATA BYTE 1
HIGH-IMPEDANCE
BIT 2047/2111
OF PAGE n
BIT 0 OF
PAGE n+1
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3638M–DFLASH–5/2013
AT45DB021D
Figure 19-2. Continuous Array Read (Opcode 0BH)
Figure 19-3. Continuous Array Read (Low Frequency: Opcode 03H)
Figure 19-4. Main Memory Page Read (Opcode: D2H)
S
CK
CS
SI
SO
MSB MSB
2310
00001011
675410119812 39424341403833 3431 3229 30 44 47 484645
OPCODE
AAAA AAAAA
MSB
XXXX XX
MSB MSB
DDDDDDDDDD
ADDRESS BITS A17 - A0 DON'T CARE
DATA BYTE 1
HIGH-IMPEDANCE
36 3735
XX
SCK
CS
SI
SO
MSB MSB
2310
00000011
675410119812 373833 36353431 3229 30 39 40
OPCODE
AAAA AAAAA
MSB MSB
DDDDDDDDDD
ADDRESS BITS A17-A0
DATA BYTE 1
HIGH-IMPEDANCE
S
CK
CS
SI
SO
MSB MSB
2310
11010010
675410119812 63666765646233 3431 3229 30 68 71 727069
OPCODE
AAAA AAAAA
MSB
XXXX XX
MSB MSB
DDDDDDDDDD
ADDRESS BITS 32 DON'T CARE BITS
DATA BYTE 1
HIGH-IMPEDANCE
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3638M–DFLASH–5/2013
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Figure 19-5. Buffer Read (Opcode D4H)
Figure 19-6. Buffer Read (Low Frequency: Opcode D1H)
Figure 19-7. Read Sector Protection Register (Opcode 32H)
S
CK
CS
SI
SO
MSB MSB
2 3 1 0
1 1 0 1 0 1 0 0
6 7 5 4 10 11 9 8 12 39 42 43 41 40 37 38 33 36 35 34 31 32 29 30 44 47 48 46 45
OPCODE
X X X X A A A X X
MSB
X X X X X X X X
MSB MSB
D D D D D D D D D D
ADDRESS BITS
BINARY PAGE SIZE = 16 DON'T CARE + BFA7-BFA0
STANDARD DATAFLASH PAGE SIZE =
15 DON'T CARE + BFA8-BFA0 DON'T CARE
DATA BYTE 1
HIGH-IMPEDANCE
SCK
CS
SI
SO
MSB MSB
2 3 1 0
1 1 0 1 0 0 0 1
6 7 5 4 10 11 9 8 12 37 38 33 36 35 34 31 32 29 30 39 40
OPCODE
X X X X A A A X X
MSB MSB
D D D D D D D D D D
DATA BYTE 1
HIGH-IMPEDANCE
ADDRESS BITS
BINARY PAGE SIZE = 16 DON'T CARE + BFA7-BFA0
STANDARD DATAFLASH PAGE SIZE =
15 DON'T CARE + BFA8-BFA0
SCK
CS
SI
SO
MSB MSB
2310
00110010
675410119812 373833 36353431 3229 30 39 40
OPCODE
XXXX XXXXX
MSB MSB
DDDDDDDDD
DON'T CARE
DATA BYTE 1
HIGH-IMPEDANCE
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3638M–DFLASH–5/2013
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Figure 19-8. Read Sector Lockdown Register (Opcode 35H)
Figure 19-9. Read Security Register (Opcode 77H)
Figure 19-10. Status Register Read (Opcode D7H)
SCK
CS
SI
SO
MSB MSB
2310
00110101
675410119812 373833 36353431 3229 30 39 40
OPCODE
XXXX XXXXX
MSB MSB
DDDDDDDDD
DON'T CARE
DATA BYTE 1
HIGH-IMPEDANCE
SCK
CS
SI
SO
MSB MSB
2310
01110111
675410119812 373833 36353431 3229 30 39 40
OPCODE
XXXX XXXXX
MSB MSB
DDDDDDDDD
DON'T CARE
DATA BYTE 1
HIGH-IMPEDANCE
SCK
CS
SI
SO
MSB
2310
11010111
675410119812 212217 20191815 1613 14 23 24
OPCODE
MSB MSB
DDDDDD DDDD
MSB
DDDDDDDD
STATUS REGISTER DATA STATUS REGISTER DATA
HIGH-IMPEDANCE
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3638M–DFLASH–5/2013
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Figure 19-11. Manufacturer and Device Read (Opcode 9FH)
20. Auto Page Rewrite Flowchart
Figure 20-1. Algorithm for Programming or Reprogramming of the Entire Array Sequentially
Notes: 1. This type of algorithm is used for applications in which the entire array is programmed sequentially, filling the array
page-by-page
2. A page can be written using either a Main Memory Page Program operation or a Buffer Write operation followed by
a Buffer to Main Memory Page Program operation
3. The algorithm above shows the programming of a single page. The algorithm will be repeated sequentially for each
page within the entire array
SCK
CS
SI
SO
60
9FH
87 38
OPCODE
1FH DEVICE ID BYTE 1 DEVICE ID BYTE 2 00H
HIGH-IMPEDANCE
14 1615 22 2423 30 3231
Note: Each transition shown for SI and SO represents one byte (8 bits)
START
MAIN MEMORY PAGE PROGRAM
THROUGH BUFFER
(82H)
END
provide address
and data
BUFFER WRITE
(84H)
BUFFER TO MAIN
MEMORY PAGE PROGRAM
(83H)
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3638M–DFLASH–5/2013
AT45DB021D
Figure 20-2. Algorithm for Randomly Modifying Data
Notes: 1. To preserve data integrity, each page of an DataFlash sector must be updated/rewritten at least once within every
10,000 cumulative page erase and program operations
2. A Page Address Pointer must be maintained to indicate which page is to be rewritten. The Auto Page Rewrite com-
mand must use the address specified by the Page Address Pointer
3. Other algorithms can be used to rewrite portions of the Flash array. Low-power applications may choose to wait
until 10,000 cumulative page erase and program operations have accumulated before rewriting all pages of the
sector. See application note AN-4 (“Using Adesto’s Serial DataFlash”) for more details
START
MAIN MEMORY PAGE
TO BUFFER TRANSFER
(53H)
INCREMENT PAGE
ADDRESS POINTER(2)
AUTO PAGE REWRITE(2)
(58H)
END
provide address of
page to modify
If planning to modify multiple
bytes currently stored within
a page of the Flash array
MAIN MEMORY PAGE PROGRAM
THROUGH BUFFER
(82H)
BUFFER WRITE
(84H)
BUFFER TO MAIN
MEMORY PAGE PROGRAM
(83H)
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21. Ordering Information
21.1 Ordering Code Detail
21.2 Green Package Options (Pb/Halide-free/RoHS Compliant)
Notes: 1. The shipping carrier option is not marked on the devices
2. Standard parts are shipped with the page size set to 264-bytes. The user is able to configure these parts to a 256-
byte page size if desired
3. Parts ordered with suffix SL954 are shipped in bulk with the page size set to 256-bytes. Parts will have a 954 or
SL954 marked on them
4. Parts ordered with suffix SL955 are shipped in tape and reel with the page size set to 256-bytes. Parts will have a
954 or SL954 marked on them
A T 4 5 D 0 2 S S H B1D– –B
Designator
Product Family
Device Density
02 = 2-megabit
Interface
1 = Serial
Package Option
M = 8-lead, 6 x 5 x 0.6mm UDFN
SS = 8-lead, 0.150" wide SOIC
S = 8-lead, 0.209" wide SOIC
Device Grade
H = NiPdAu lead finish, industrial
temperature range (-40°C to +85°C)
Shipping Carrier Option
B = Bulk (tubes)
Y = Trays
T = Tape and reel
D
e
vi
ce
R
e
vi
s
i
o
n
Ordering Code(1)(2) Package Lead Finish Operating Voltage fSCK (MHz) Operation Range
AT45DB021D-MH-Y
AT45DB021D-MH-T
AT45DB021D-MH-SL954(3)
AT45DB021D-MH-SL955(4)
8MA1
NiPdAu 2.7V to 3.6V 66 Industrial
(-40°C to +85°C)
AT45DB021D-SSH-B
AT45DB021D-SSH-T
AT45DB021D-SSH-SL954(3)
AT45DB021D-SSH-SL955(4)
8S1
AT45DB021D-SH-B
AT45DB021D-SH-T
AT45DB021D-SH-SL954(3)
AT45DB021D-SH-SL955(4)
8S2
Package Type
8MA1 8-lead (6 x 5 x 0.6mm Body), Thermally Enhanced Plastic Ultra Thin Dual Flat No Lead Package (UDFN)
8S1 8-lead, 0.150” Wide, Plastic Gull Wing Small Outline Package (JEDEC SOIC)
8S2 8-lead, 0.209” Wide, Plastic Gull Wing Small Outline Package (EIAJ SOIC)
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22. Packaging Information
22.1 8MA1 – UDFN
TITLE DRAWING NO.GPC REV.
Package Drawing Contact:
contact@adestotech.com 8MA1 YFG D
8MA1, 8-pad (5 x 6 x 0.6 mm Body), Thermally
Enhanced Plastic Ultra Thin Dual Flat No Lead
Package (UDFN)
COMMON DIMENSIONS
(Unit of Measure = mm)
SYMBOL MIN NOM MAX N O T E
A 0.45 0.55 0.60
A1 0.00 0.02 0.05
b 0.35 0.40 0.48
C 0.152 REF
D 4.90 5.00 5.10
D2 3.80 4.00 4.20
E 5.90 6.00 6.10
E2 3.20 3.40 3.60
e 1.27
L 0.50 0.60 0.75
y 0.00 – 0.08
K 0.20 – –
4/15/08
Pin 1 ID
TOP VIEW
E
D
A1
A
SIDE VIEW
y
C
BOTTOM VIEW
E2
D2
L
b
e
1
2
3
4
8
7
6
5
Pin #1 Notch
(0.20 R)
0.45
K
Pin #1
Cham f e r
(C 0.35)
Option A
(Option B)
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22.2 8S1 – JEDEC SOIC
DRAWING NO. REV. TITLE GPC
COMMON DIMENSIONS
(Unit of Measure = mm)
SYMBOL MIN NOM MAX NOTE
A1 0.10 – 0.25
A 1.35 – 1.75
b 0.31 – 0.51
C 0.17 – 0.25
D 4.80 – 5.05
E1 3.81 – 3.99
E 5.79 – 6.20
e 1.27 BSC
L 0.40 – 1.27
Ø
Ø
0° – 8°
Ø
E
1
N
TOP VIEW
C
E1
END VIEW
A
b
L
A1
e
D
SIDE VIEW
Package Drawing Contact:
contact@adestotech.com
8S1 G
6/22/11
Notes: This drawing is for general information only.
Refer to JEDEC Drawing MS-012, Variation AA
for proper dimensions, tolerances, datums, etc.
8S1, 8-lead (0.150” Wide Body), Plastic Gull Wing
Small Outline (JEDEC SOIC) SWB
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3638M–DFLASH–5/2013
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22.3 8S2 – EIAJ SOIC
TITLE DRAWING NO. GPC REV.
Package Drawing Contact:
contact@adestotech.com
8S2 STN F
8S2, 8-lead, 0.208” Body, Plastic Small
Outline Package (EIAJ)
4/15/08
COMMON DIMENSIONS
(Unit of Measure = mm)
SYMBOL MIN NOM MAX NOTE
Notes: 1. This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information.
2. Mismatch of the upper and lower dies and resin burrs aren't included.
3. Determines the true geometric position.
4. Values b,C apply to plated terminal. The standard thickness of the plating layer shall measure between 0.007 to .021 mm.
A 1.70 2.16
A1 0.05 0.25
b 0.35 0.48 4
C 0.15 0.35 4
D 5.13 5.35
E1 5.18 5.40 2
E 7.70 8.26
L 0.51 0.85
q 0° 8°
e 1.27 BSC 3
q
q
1
1
N
N
E
E
TOP VIEW
TOP VIEW
C
C
E1
E1
END VIEW
END VIEW
A
A
b
b
L
L
A1
A1
e
e
D
D
SIDE VIEW
SIDE VIEW
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23. Revision History
Doc. Rev. Date Comments
A 06/2006 Initial release.
B 02/2007 Removed RDY/BUSY pin references.
C 08/2007
Changed tVCSL time to 1ms
Changed IDP (Max) to 15μA
Added Chip Erase time
Changed tRDPD time to 35μs
Fixed the typographical error in the Block Architecture diagram
D 11/2007
Changed the tXFR and tCOMP times from 400μs to 200μs
Changed part number ordering code to reflect NiPdAu lead finish
- Changed AT45DB021D-MU to AT45DB021D-MH
- Changed AT45DB021D-SSU to AT45DB021D-SSH
- Changed AT45DB021D-SU to AT45DB021D-SH
Added lead finish details to Ordering Information table
Added Ordering Code Detail
E 02/2008 Fixed the typographical error, under Status Register Read, to indicate that bit 3 is a “0”
F 04/2008 Replaced 8M1-A MLF Package with 8MA1 UDFN Package
Added part number ordering code details for suffixes SL954/955
G 02/2009 Changed tDIS (Typ and Max) to 27ns and 35ns, respectively
H 03/2009
Changed Deep Power-Down Current values
- Increased typical value from 5μA to 15μA
- Increased maximum value from 15μA to 25μA
I 04/2009 Updated Absolute Maximum Ratings
Updated System Specifications
J 05/2010
Updated template
Changed number of bytes and sectors in Section 7.1.2 on page 13
Changed TSE values in Table 16-3 on page 31
- Typ from 0.8 to 400, Max from 2.5 to 700 and Units from s to ms
Changed BA0 to PA0 and x to P under PA3, row 50h in Table 13-7 on page 27
Changed A11 from x to P, row 50h in Table 13-6 on page 26
Changed from 10,000 to 20,000 cumulative page erase/program operations in Section 9.3
Added “Please contact Adesto for availability of devices that are specified to exceed the 20K
cycle cumulative limit” in Section 9.3
K 11/2012 Update to Adesto Logos
L 1/2013 Fix block size and number of sectors in waveforms
M 5/2013 Added “Not Recommended for New Designs.” Updated copyright date, registered logo
trademarks, and revision date.
Corporate Office
California | USA
Adesto Headquarters
1250 Borregas Avenue
Sunnyvale, CA 94089
Phone: (+1) 408.400.0578
Email: contact@adestotech.com
© 2013 Adesto Technologies. All rights reserved. / Rev.: 3638M–DFLASH–5/2013
Disclaimer: Adesto Technologies Corporation makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in Adesto's Terms
and Conditions located on the Company's web site. The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications
detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Adesto are granted by the
Company in connection with the sale of Adesto products, expressly or by implication. Adesto's products are not authorized for use as critical components in life support devices or systems.
Adesto®, the Adesto logo, CBRAM®, and DataFlash® are registered trademarks or trademarks of Adesto Technologies. All other marks are the property of their respective
owners.
