©2006 Silicon Storage Technology, Inc.
S71231-07-000 10/06
1
The SST logo and SuperFlash are registered Trademarks of Silicon Storage Technology, Inc.
These specifications are subject to change without notice.
Data Sheet
FEATURES:
Single 2.7-3.6V Read and Write Operations
Serial Interface Architecture
SPI Compatible: Mode 0 and Mode 3
20 MHz Max Clock Frequency
Superior Reliability
Endurance: 100,000 Cycles (typical)
Greater than 100 years Data Retention
Low Power Consumption:
Active Read Current: 7 mA (typical)
Standby Current: 8 µA (typical)
Flexible Erase Capability
Uniform 4 KByte sectors
Uniform 32 KByte overlay blocks
Fast Erase and Byte-Program:
Chip-Erase Time: 70 ms (typical)
Sector- or Block-Erase Time: 18 ms (typical)
Byte-Program Time: 14 µs (typical)
Auto Address Increment (AAI) Programming
Decrease total chip programming time over
Byte-Program operations
End-of-Write Detection
Software Status
Hold Pin (HOLD#)
Suspends a serial sequence to the memory
without deselecting the device
Write Protection (WP#)
Enables/Disables the Lock-Down function of the
status register
Software Write Protection
Write protection through Block-Protection bits in
status register
Temperature Range
Commercial: 0°C to +70°C
Industrial: -40°C to +85°C
Extended: -20°C to +85°C
Packages Available
8-lead SOIC 150 mil body width
8-contact WSON (5mm x 6mm)
All non-Pb (lead-free) devices are RoHS compliant
PRODUCT DESCRIPTION
The SST serial flash family features a four-wire, SPI-
compatible interface that allows for a low pin-count pack-
age occupying less board space and ultimately lowering
total system costs. SST25VF020 SPI serial flash memo-
ries are manufactured with SST’s proprietary, high perfor-
mance CMOS SuperFlash Technology. The split-gate
cell design and thick-oxide tunneling injector attain better
reliability and manufacturability compared with alternate
approaches.
The SST25VF020 device significantly improves perfor-
mance, while lowering power consumption. The total
energy consumed is a function of the applied voltage, cur-
rent, and time of application. Since for any given voltage
range, the SuperFlash technology uses less current to
program and has a shorter erase time, the total energy
consumed during any Erase or Program operation is less
than alternative flash memory technologies. The
SST25VF020 device operates with a single 2.7-3.6V
power supply.
The SST25VF020 device is offered in an 8-lead SOIC 150
mil body width (SA) package, and in an 8-contact WSON
package. See Figure 2 for the pin assignments.
2 Mbit SPI Serial Flash
SST25VF020
SST25VF020 / 0402Mb / 4Mb Serial Peripheral Interface (SPI) flash memory
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2
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
FIGURE 1: Functional Block Diagram
1231 B1.0
I/O Buffers
and
Data Latches
SuperFlash
Memory
X - Decoder
Control Logic
Address
Buffers
and
Latches
CE#
Y - Decoder
SCK SI SO WP# HOLD#
Serial Interface
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
3
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
PIN DESCRIPTION
FIGURE 2: Pin Assignments
TABLE 1: Pin Description
Symbol Pin Name Functions
SCK Serial Clock To provide the timing of the serial interface.
Commands, addresses, or input data are latched on the rising edge of the clock input, while output
data is shifted out on the falling edge of the clock input.
SI Serial Data
Input
To transfer commands, addresses, or data serially into the device.
Inputs are latched on the rising edge of the serial clock.
SO Serial Data
Output
To transfer data serially out of the device.
Data is shifted out on the falling edge of the serial clock.
CE# Chip Enable The device is enabled by a high to low transition on CE#. CE# must remain low for the duration of
any command sequence.
WP# Write Protect The Write Protect (WP#) pin is used to enable/disable BPL bit in the status register.
HOLD# Hold To temporarily stop serial communication with SPI flash memory without resetting the device.
VDD Power Supply To provide power supply (2.7-3.6V).
VSS Ground
T1.0 1231
8-LEAD SOIC 8-CONTACT WSON
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
Top View
VDD
HOLD#
SCK
SI
1231 08-wson P2.0
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
VDD
HOLD#
SCK
SI
Top View
1231 08-soic P1.0
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4
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
PRODUCT IDENTIFICATION
MEMORY ORGANIZATION
The SST25VF020 SuperFlash memory array is organized
in 4 KByte sectors with 32 KByte overlay blocks.
DEVICE OPERATION
The SST25VF020 is accessed through the SPI (Serial
Peripheral Interface) bus compatible protocol. The SPI bus
consist of four control lines; Chip Enable (CE#) is used to
select the device, and data is accessed through the Serial
Data Input (SI), Serial Data Output (SO), and Serial Clock
(SCK).
The SST25VF020 supports both Mode 0 (0,0) and Mode 3
(1,1) of SPI bus operations. The difference between the
two modes, as shown in Figure 3, is the state of the SCK
signal when the bus master is in Stand-by mode and no
data is being transferred. The SCK signal is low for Mode 0
and SCK signal is high for Mode 3. For both modes, the
Serial Data In (SI) is sampled at the rising edge of the SCK
clock signal and the Serial Data Output (SO) is driven after
the falling edge of the SCK clock signal.
FIGURE 3: SPI Protocol
TABLE 2: Product Identification
Address Data
Manufacturer’s ID 00000H BFH
Device ID
SST25VF020 00001H 43H
T2.0 1231
1231 F02.1
MODE 3
SCK
SI
SO
CE#
MODE 3
DON'T CARE
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MODE 0MODE 0
HIGH IMPEDANCE
MSB
MSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
5
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Hold Operation
HOLD# pin is used to pause a serial sequence underway
with the SPI flash memory without resetting the clocking
sequence. To activate the HOLD# mode, CE# must be in
active low state. The HOLD# mode begins when the SCK
active low state coincides with the falling edge of the
HOLD# signal. The HOLD mode ends when the HOLD#
signal’s rising edge coincides with the SCK active low state.
If the falling edge of the HOLD# signal does not coincide
with the SCK active low state, then the device enters Hold
mode when the SCK next reaches the active low state.
Similarly, if the rising edge of the HOLD# signal does not
coincide with the SCK active low state, then the device
exits in Hold mode when the SCK next reaches the active
low state. See Figure 4 for Hold Condition waveform.
Once the device enters Hold mode, SO will be in high-
impedance state while SI and SCK can be VIL or VIH.
If CE# is driven active high during a Hold condition, it
returns the device to standby mode. As long as HOLD#
signal is low, the memory remains in the Hold condition. To
resume communication with the device, HOLD# must be
driven active high, and CE# must be driven active low. See
Figure 18 for Hold timing.
FIGURE 4: Hold Condition Waveform
Write Protection
SST25VF020 provides software Write protection. The
Write Protect pin (WP#) enables or disables the lock-down
function of the status register. The Block-Protection bits
(BP1, BP0, and BPL) in the status register provide Write
protection to the memory array and the status register. See
Table 5 for Block-Protection description.
Write Protect Pin (WP#)
The Write Protect (WP#) pin enables the lock-down func-
tion of the BPL bit (bit 7) in the status register. When WP#
is driven low, the execution of the Write-Status-Register
(WRSR) instruction is determined by the value of the BPL
bit (see Table 3). When WP# is high, the lock-down func-
tion of the BPL bit is disabled.
Active Hold Active Hold Active
1231 F03.0
SCK
HOLD#
TABLE 3: Conditions to execute Write-Status-
Register (WRSR) Instruction
WP# BPL Execute WRSR Instruction
L 1 Not Allowed
L0Allowed
HXAllowed
T3.0 1231
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6
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Status Register
The software status register provides status on whether the
flash memory array is available for any Read or Write oper-
ation, whether the device is Write enabled, and the state of
the memory Write protection. During an internal Erase or
Program operation, the status register may be read only to
determine the completion of an operation in progress.
Table 4 describes the function of each bit in the software
status register.
Busy
The Busy bit determines whether there is an internal Erase
or Program operation in progress. A “1” for the Busy bit indi-
cates the device is busy with an operation in progress. A “0”
indicates the device is ready for the next valid operation.
Write Enable Latch (WEL)
The Write-Enable-Latch bit indicates the status of the inter-
nal memory Write Enable Latch. If the Write-Enable-Latch
bit is set to “1”, it indicates the device is Write enabled. If the
bit is set to “0” (reset), it indicates the device is not Write
enabled and does not accept any memory Write (Program/
Erase) commands. The Write-Enable-Latch bit is automati-
cally reset under the following conditions:
Power-up
Write-Disable (WRDI) instruction completion
Byte-Program instruction completion
Auto Address Increment (AAI) programming
reached its highest memory address
Sector-Erase instruction completion
Block-Erase instruction completion
Chip-Erase instruction completion
TABLE 4: Software Status Register
Bit Name Function
Default at
Power-up Read/Write
0 BUSY 1 = Internal Write operation is in progress
0 = No internal Write operation is in progress
0R
1 WEL 1 = Device is memory Write enabled
0 = Device is not memory Write enabled
0R
2 BP0 Indicate current level of block write protection (See Table 5) 1 R/W
3 BP1 Indicate current level of block write protection (See Table 5) 1 R/W
4:5 RES Reserved for future use 0 N/A
6 AAI Auto Address Increment Programming status
1 = AAI programming mode
0 = Byte-Program mode
0R
7 BPL 1 = BP1, BP0 are read-only bits
0 = BP1, BP0 are read/writable
0R/W
T4.0 1231
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
7
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Block Protection (BP1, BP0)
The Block-Protection (BP1, BP0) bits define the size of the
memory area, as defined in Table 5, to be software pro-
tected against any memory Write (Program or Erase)
operations. The Write-Status-Register (WRSR) instruction
is used to program the BP1 and BP0 bits as long as WP#
is high or the Block-Protect-Lock (BPL) bit is 0. Chip-Erase
can only be executed if Block-Protection bits are both 0.
After power-up, BP1 and BP0 are set to 1.
Block Protection Lock-Down (BPL)
WP# pin driven low (VIL), enables the Block-Protection-
Lock-Down (BPL) bit. When BPL is set to 1, it prevents any
further alteration of the BPL, BP1, and BP0 bits. When the
WP# pin is driven high (VIH), the BPL bit has no effect and
its value is “Don’t Care”. After power-up, the BPL bit is
reset to 0.
Auto Address Increment (AAI)
The Auto Address Increment Programming-Status bit pro-
vides status on whether the device is in AAI programming
mode or Byte-Program mode. The default at power up is
Byte-Program mode.
TABLE 5: Software Status Register Block Protection1
1. Default at power-up for BP1 and BP0 is ‘11’.
Protection Level
Status
Register
Bit
Protected Memory Area
BP1 BP0 2 Mbit
000None
1 (1/4 Memory Array) 0 1 030000H-03FFFFH
2 (1/2 Memory Array) 1 0 020000H-03FFFFH
3 (Full Memory Array) 1 1 000000H-03FFFFH
T5.0 1231
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Instructions
Instructions are used to Read, Write (Erase and Program),
and configure the SST25VF020. The instruction bus cycles
are 8 bits each for commands (Op Code), data, and
addresses. Prior to executing any Byte-Program, Auto
Address Increment (AAI) programming, Sector-Erase,
Block-Erase, or Chip-Erase instructions, the Write-Enable
(WREN) instruction must be executed first. The complete
list of the instructions is provided in Table 6. All instructions
are synchronized off a high to low transition of CE#. Inputs
will be accepted on the rising edge of SCK starting with the
most significant bit. CE# must be driven low before an
instruction is entered and must be driven high after the last
bit of the instruction has been shifted in (except for Read,
Read-ID and Read-Status-Register instructions). Any low
to high transition on CE#, before receiving the last bit of an
instruction bus cycle, will terminate the instruction in
progress and return the device to the standby mode.
Instruction commands (Op Code), addresses, and data are
all input from the most significant bit (MSB) first.
TABLE 6: Device Operation Instructions1
1. AMS = Most Significant Address
AMS = A17 for SST25VF020
Address bits above the most significant bit of each density can be VIL or VIH
Bus Cycle2
2. One bus cycle is eight clock periods.
123 4 5
Cycle Type/Operation3,4
3. Operation: SIN = Serial In, SOUT = Serial Out
4. X = Dummy Input Cycles (VIL or VIH); - = Non-Applicable Cycles (Cycles are not necessary)
SIN SOUT SIN SOUT SIN SOUT SIN SOUT SIN SOUT
Read 03H Hi-Z A23-A16 Hi-Z A15-A8Hi-Z A7-A0Hi-Z X DOUT
Sector-Erase5,6
5. Sector addresses: use AMS-A12, remaining addresses can be VIL or VIH
6. Prior to any Byte-Program, AAI-Program, Sector-Erase, Block-Erase, or Chip-Erase operation, the Write-Enable (WREN) instruction
must be executed.
20H Hi-Z A23-A16 Hi-Z A15-A8Hi-Z A7-A0Hi-Z - -
Block-Erase5,7
7. Block addresses for: use AMS-A15, remaining addresses can be VIL or VIH
52H Hi-Z A23-A16 Hi-Z A15-A8Hi-Z A7-A0Hi-Z - -
Chip-Erase660H Hi-Z - - - - - - - -
Byte-Program602H Hi-Z A23-A16 Hi-Z A15-A8Hi-Z A7-A0Hi-Z DIN Hi-Z
Auto Address Increment (AAI) Program6,8
8. To continue programming to the next sequential address location, enter the 8-bit command, AFH,
followed by the data to be programmed.
AFH Hi-Z A23-A16 Hi-Z A15-A8Hi-Z A7-A0Hi-Z DIN Hi-Z
Read-Status-Register (RDSR) 05H Hi-Z X DOUT -Note
9
9. The Read-Status-Register is continuous with ongoing clock cycles until terminated by a low to high transition on CE#.
-Note
9-Note
9
Enable-Write-Status-Register (EWSR)10
10. The Enable-Write-Status-Register (EWSR) instruction and the Write-Status-Register (WRSR) instruction must work in conjunction of
each other. The WRSR instruction must be executed immediately (very next bus cycle) after the EWSR instruction to make both
instructions effective.
50H Hi-Z - - - - - - - -
Write-Status-Register (WRSR)10 01H Hi-Z Data Hi-Z - - -. - - -
Write-Enable (WREN) 06H Hi-Z - - - - - - - -
Write-Disable (WRDI) 04H Hi-Z - - - - - - - -
Read-ID 90H or
ABH
Hi-Z 00H Hi-Z 00H Hi-Z ID Addr11
11. Manufacturer’s ID is read with A0=0, and Device ID is read with A0=1. All other address bits are 00H. The Manufacturer’s and Device
ID output stream is continuous until terminated by a low to high transition on CE#
Hi-Z X DOUT12
12. Device ID = 43H for SST25VF020
T6.0 1231
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
9
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Read
The Read instruction outputs the data starting from the
specified address location. The data output stream is con-
tinuous through all addresses until terminated by a low to
high transition on CE#. The internal address pointer will
automatically increment until the highest memory address
is reached. Once the highest memory address is reached,
the address pointer will automatically increment to the
beginning (wrap-around) of the address space, i.e. for
2 Mbit density, once the data from address location
3FFFFH had been read, the next output will be from
address location 00000H.
The Read instruction is initiated by executing an 8-bit com-
mand, 03H, followed by address bits [A23-A0]. CE# must
remain active low for the duration of the Read cycle. See
Figure 5 for the Read sequence.
FIGURE 5: READ SEQUENCE
Byte-Program
The Byte-Program instruction programs the bits in the
selected byte to the desired data. The selected byte must
be in the erased state (FFH) when initiating a Program
operation. A Byte-Program instruction applied to a pro-
tected memory area will be ignored.
Prior to any Write operation, the Write-Enable (WREN)
instruction must be executed. CE# must remain active low
for the duration of the Byte-Program instruction. The Byte-
Program instruction is initiated by executing an 8-bit com-
mand, 02H, followed by address bits [A23-A0]. Following the
address, the data is input in order from MSB (bit 7) to LSB
(bit 0). CE# must be driven high before the instruction is
executed. The user may poll the Busy bit in the software
status register or wait TBP for the completion of the internal
self-timed Byte-Program operation. See Figure 6 for the
Byte-Program sequence.
FIGURE 6: Byte-Program Sequence
1231 F04.1
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
03
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 7047 48 55 56 63 64
N+2 N+3 N+4N N+1
DOUT
MSB MSB
MSB
MODE 0
MODE 3
DOUT DOUT DOUT DOUT
1231 F05.1
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD. DIN
02
HIGH IMPEDANCE
15 16 23 24 31 32 39
MODE 0
MODE 3
MSBMSB
MSB LSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Auto Address Increment (AAI) Program
The AAI program instruction allows multiple bytes of data to
be programmed without re-issuing the next sequential
address location. This feature decreases total program-
ming time when the entire memory array is to be pro-
grammed. An AAI program instruction pointing to a
protected memory area will be ignored. The selected
address range must be in the erased state (FFH) when ini-
tiating an AAI program instruction.
Prior to any write operation, the Write-Enable (WREN)
instruction must be executed. The AAI program instruction
is initiated by executing an 8-bit command, AFH, followed
by address bits [A23-A0]. Following the addresses, the data
is input sequentially from MSB (bit 7) to LSB (bit 0). CE#
must be driven high before the AAI program instruction is
executed. The user must poll the BUSY bit in the software
status register or wait TBP for the completion of each inter-
nal self-timed Byte-Program cycle. Once the device com-
pletes programming byte, the next sequential address may
be program, enter the 8-bit command, AFH, followed by the
data to be programmed. When the last desired byte had
been programmed, execute the Write-Disable (WRDI)
instruction, 04H, to terminate AAI. After execution of the
WRDI command, the user must poll the Status register to
ensure the device completes programming. See Figure 7
for AAI programming sequence.
There is no wrap mode during AAI programming; once the
highest unprotected memory address is reached, the
device will exit AAI operation and reset the Write-Enable-
Latch bit (WEL = 0).
FIGURE 7: Auto Address Increment (AAI) Program Sequence
CE#
SI
SCK
A[23:16] A[15:8] A[7:0]
AF Data Byte 1 AF Data Byte 2
CE#
SI
SO
SCK
Write Disable (WRDI)
Instruction to terminate
AAI Operation
Read Status Register (RDSR)
Instruction to verify end of
AAI Operation
04Last Data ByteAF 05
DOUT
MODE 3
MODE 0
TBP TBP
TBP
1231 F06.1
0 1 2 3 4 5 6 7 8 323334353637383915 16 23 24 31 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 01
012345670123456789101112131415 0123456789101112131415
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
11
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Sector-Erase
The Sector-Erase instruction clears all bits in the selected 4
KByte sector to FFH. A Sector-Erase instruction applied to
a protected memory area will be ignored. Prior to any Write
operation, the Write-Enable (WREN) instruction must be
executed. CE# must remain active low for the duration of
the any command sequence. The Sector-Erase instruction
is initiated by executing an 8-bit command, 20H, followed
by address bits [A23-A0]. Address bits [AMS-A12]
(AMS = Most Significant address) are used to determine the
sector address (SAX), remaining address bits can be VIL or
VIH. CE# must be driven high before the instruction is exe-
cuted. The user may poll the Busy bit in the software status
register or wait TSE for the completion of the internal self-
timed Sector-Erase cycle. See Figure 8 for the Sector-
Erase sequence.
FIGURE 8: Sector-Erase Sequence
Block-Erase
The Block-Erase instruction clears all bits in the selected 32
KByte block to FFH. A Block-Erase instruction applied to a
protected memory area will be ignored. Prior to any Write
operation, the Write-Enable (WREN) instruction must be
executed. CE# must remain active low for the duration of
any command sequence. The Block-Erase instruction is
initiated by executing an 8-bit command, 52H, followed by
address bits [A23-A0]. Address bits [AMS-A15] (AMS = Most
significant address) are used to determine block address
(BAX), remaining address bits can be VIL or VIH. CE# must
be driven high before the instruction is executed. The user
may poll the Busy bit in the software status register or wait
TBE for the completion of the internal self-timed Block-
Erase cycle. See Figure 9 for the Block-Erase sequence.
FIGURE 9: Block-Erase Sequence
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
20
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1231 F07.1
MSBMSB
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
52
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1231 F08.1
MSB MSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Chip-Erase
The Chip-Erase instruction clears all bits in the device to
FFH. A Chip-Erase instruction will be ignored if any of the
memory area is protected. Prior to any Write operation, the
Write-Enable (WREN) instruction must be executed. CE#
must remain active low for the duration of the Chip-Erase
instruction sequence. The Chip-Erase instruction is initiated
by executing an 8-bit command, 60H. CE# must be driven
high before the instruction is executed. The user may poll
the Busy bit in the software status register or wait TCE for
the completion of the internal self-timed Chip-Erase cycle.
See Figure 10 for the Chip-Erase sequence.
FIGURE 10: Chip-Erase Sequence
Read-Status-Register (RDSR)
The Read-Status-Register (RDSR) instruction allows read-
ing of the status register. The status register may be read at
any time even during a Write (Program/Erase) operation.
When a Write operation is in progress, the Busy bit may be
checked before sending any new commands to assure that
the new commands are properly received by the device.
CE# must be driven low before the RDSR instruction is
entered and remain low until the status data is read. Read-
Status-Register is continuous with ongoing clock cycles
until it is terminated by a low to high transition of the CE#.
See Figure 11 for the RDSR instruction sequence.
FIGURE 11: Read-Status-Register (RDSR) Sequence
CE#
SO
SI
SCK
01234567
60
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F09.1
MSB
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1231 F10.1
MODE 3
SCK
SI
SO
CE#
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
05
MODE 0
HIGH IMPEDANCE
Status
Register Out
MSB
MSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
13
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Write-Enable (WREN)
The Write-Enable (WREN) instruction sets the Write-
Enable-Latch bit to 1 allowing Write operations to occur.
The WREN instruction must be executed prior to any Write
(Program/Erase) operation. CE# must be driven high
before the WREN instruction is executed.
FIGURE 12: Write Enable (WREN) Sequence
Write-Disable (WRDI)
The Write-Disable (WRDI) instruction resets the Write-
Enable-Latch bit and AAI bit to 0 disabling any new Write
operations from occurring. CE# must be driven high before
the WRDI instruction is executed.
FIGURE 13: Write Disable (WRDI) Sequence
Enable-Write-Status-Register (EWSR)
The Enable-Write-Status-Register (EWSR) instruction
arms the Write-Status-Register (WRSR) instruction and
opens the status register for alteration. The Enable-Write-
Status-Register instruction does not have any effect and
will be wasted, if it is not followed immediately by the Write-
Status-Register (WRSR) instruction. CE# must be driven
low before the EWSR instruction is entered and must be
driven high before the EWSR instruction is executed.
CE#
SO
SI
SCK
01234567
06
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F11.1
MSB
CE#
SO
SI
SCK
01234567
04
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F12.1
MSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Write-Status-Register (WRSR)
The Write-Status-Register instruction works in conjunction
with the Enable-Write-Status-Register (EWSR) instruction
to write new values to the BP1, BP0, and BPL bits of the
status register. The Write-Status-Register instruction must
be executed immediately after the execution of the Enable-
Write-Status-Register instruction (very next instruction bus
cycle). This two-step instruction sequence of the EWSR
instruction followed by the WRSR instruction works like
SDP (software data protection) command structure which
prevents any accidental alteration of the status register val-
ues. The Write-Status-Register instruction will be ignored
when WP# is low and BPL bit is set to “1”. When the WP#
is low, the BPL bit can only be set from “0” to “1” to lock-
down the status register, but cannot be reset from “1” to “0”.
When WP# is high, the lock-down function of the BPL bit is
disabled and the BPL, BP0, and BP1 bits in the status reg-
ister can all be changed. As long as BPL bit is set to 0 or
WP# pin is driven high (VIH) prior to the low-to-high transi-
tion of the CE# pin at the end of the WRSR instruction, the
BP0, BP1, and BPL bit in the status register can all be
altered by the WRSR instruction. In this case, a single
WRSR instruction can set the BPL bit to “1” to lock down
the status register as well as altering the BP0 and BP1 bit
at the same time. See Table 3 for a summary description of
WP# and BPL functions. CE# must be driven low before
the command sequence of the WRSR instruction is
entered and driven high before the WRSR instruction is
executed. See Figure 14 for EWSR and WRSR instruction
sequences.
FIGURE 14: Enable-Write-Status-Register (EWSR) and Write-Status-Register (WRSR) Sequence
1231 F13.1
MODE 3
HIGH IMPEDANCE
MODE 0
STATUS
REGISTER IN
76543210
MSBMSBMSB
01
MODE 3
SCK
SI
SO
CE#
MODE 0
50
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
15
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
Read-ID
The Read-ID instruction identifies the device as
SST25VF020 and manufacturer as SST. The device infor-
mation can be read from executing an 8-bit command, 90H
or ABH, followed by address bits [A23-A0]. Following the
Read-ID instruction, the manufacturer’s ID is located in
address 00000H and the device ID is located in address
00001H. Once the device is in Read-ID mode, the manu-
facturer’s and device ID output data toggles between
address 00000H and 00001H until terminated by a low to
high transition on CE#.
FIGURE 15: Read-ID Sequence
1231 F14.1
CE#
SO
SI
SCK
00
012345678
00 ADD1
90 or AB
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 47 48 55 56 63
BF Device ID BF Device ID
Note: The manufacturer's and device ID output stream is continuous until terminated by a low to high transition on CE#.
1. 00H will output the manfacturer's ID first and 01H will output device ID first before toggling between the two.
HIGH
IMPEDANCE
MODE 3
MODE 0
MSB MSB
MSB
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16
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
ELECTRICAL SPECIFICATIONS
Absolute Maximum Stress Ratings (Applied conditions greater than those listed under “Absolute Maximum
Stress Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation
of the device at these conditions or conditions greater than those defined in the operational sections of this data
sheet is not implied. Exposure to absolute maximum stress rating conditions may affect device reliability.)
Temperature Under Bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C
D. C. Voltage on Any Pin to Ground Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to VDD+0.5V
Transient Voltage (<20 ns) on Any Pin to Ground Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -2.0V to VDD+2.0V
Package Power Dissipation Capability (Ta = 25°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0W
Surface Mount Solder Reflow Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C for 10 seconds
Output Short Circuit Current1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 mA
1. Output shorted for no more than one second. No more than one output shorted at a time.
OPERATING RANGE
Range Ambient Temp VDD
Commercial 0°C to +70°C 2.7-3.6V
Industrial -40°C to +85°C 2.7-3.6V
Extended -20°C to +85°C 2.7-3.6V
AC CONDITIONS OF TEST
Input Rise/Fall Time . . . . . . . . . . . . . . . 5 ns
Output Load . . . . . . . . . . . . . . . . . . . . . CL = 30 pF
See Figures 20 and 21
TABLE 7: DC Operating Characteristics VDD = 2.7-3.6V
Symbol Parameter
Limits
Test ConditionsMin Max Units
IDDR Read Current 10 mA CE#=0.1 VDD/0.9 VDD@20 MHz, SO=open
IDDW Program and Erase Current 30 mA CE#=VDD
ISB Standby Current 15 µA CE#=VDD, VIN=VDD or VSS
ILI Input Leakage Current 1 µA VIN=GND to VDD, VDD=VDD Max
ILO Output Leakage Current 1 µA VOUT=GND to VDD, VDD=VDD Max
VIL Input Low Voltage 0.8 V VDD=VDD Min
VIH Input High Voltage 0.7 VDD VV
DD=VDD Max
VOL Output Low Voltage 0.2 V IOL=100 µA, VDD=VDD Min
VOH Output High Voltage VDD-0.2 V IOH=-100 µA, VDD=VDD Min
T7.0 1231
TABLE 8: Recommended System Power-up Timings
Symbol Parameter Minimum Units
TPU-READ1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
VDD Min to Read Operation 10 µs
TPU-WRITE1VDD Min to Write Operation 10 µs
T8.0 1231
TABLE 9: Capacitance (Ta = 25°C, f=1 Mhz, other pins open)
Parameter Description Test Condition Maximum
COUT1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
Output Pin Capacitance VOUT = 0V 12 pF
CIN1Input Capacitance VIN = 0V 6 pF
T9.0 1231
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
17
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
TABLE 10: Reliability Characteristics
Symbol Parameter Minimum Specification Units Test Method
NEND1Endurance 10,000 Cycles JEDEC Standard A117
TDR1Data Retention 100 Years JEDEC Standard A103
ILTH1Latch Up 100 + IDD mA JEDEC Standard 78
T10.0 1231
1. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
TABLE 11: AC Operating Characteristics VDD = 2.7-3.6V
Symbol Parameter
Limits
Min Max Units
FCLK Serial Clock Frequency 20 MHz
TSCKH Serial Clock High Time 20 ns
TSCKL Serial Clock Low Time 20 ns
TSCKR Serial Clock Rise Time 5 ns
TSCKF Serial Clock Fall Time 5 ns
TCES1
1. Relative to SCK.
CE# Active Setup Time 20 ns
TCEH1CE# Active Hold Time 20 ns
TCHS1CE# Not Active Setup Time 10 ns
TCHH1CE# Not Active Hold Time 10 ns
TCPH CE# High Time 100 ns
TCHZ CE# High to High-Z Output 20 ns
TCLZ SCK Low to Low-Z Output 0 ns
TDS Data In Setup Time 4 ns
TDH Data In Hold Time 5 ns
THLS HOLD# Low Setup Time 10 ns
THHS HOLD# High Setup Time 10 ns
THLH HOLD# Low Hold Time 15 ns
THHH HOLD# High Hold Time 10 ns
THZ HOLD# Low to High-Z Output 20 ns
TLZ HOLD# High to Low-Z Output 20 ns
TOH Output Hold from SCK Change 0 ns
TVOutput Valid from SCK 23 ns
TSE Sector-Erase 25 ms
TBE Block-Erase 25 ms
TSCE Chip-Erase 100 ms
TBP Byte-Program 20 µs
T11.2 1231
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18
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
FIGURE 16: Serial Input Timing Diagram
FIGURE 17: Serial Output Timing Diagram
HIGH-Z HIGH-Z
CE#
SO
SI
SCK
MSB LSB
TDS TDH
TCHH
TCES TCEH TCHS
TSCKR
TSCKF
TCPH
1231 F15.0
1231 F16.0
CE#
SI
SO
SCK
MSB
TCLZ
TV
TSCKH
TCHZ
TOH
TSCKL
LSB
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
19
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
FIGURE 18: Hold Timing Diagram
FIGURE 19: Power-up Timing Diagram
THZ TLZ
THHH THLS
THLH
THHS
1231 F17.0
HOLD#
CE#
SCK
SO
SI
Time
VDD Min
VDD Max
VDD
Device fully accessible
TPU-READ
TPU-WRITE
Chip selection is not allowed.
All commands are rejected by the device.
1231 F18.0
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20
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
FIGURE 20: AC Input/Output Reference Waveforms
FIGURE 21: A Test Load Example
1231 F19.1
REFERENCE POINTS OUTPUTINPUT?
VHT
VLT
VHT
VLT
VIHT
VILT
AC test inputs are driven at VIHT (0.9VDD) for a logic “1” and VILT (0.1VDD) for a logic “0”. Measurement reference points
for inputs and outputs are VHT (0.7VDD) and VLT (0.3VDD). Input rise and fall times (10% 90%) are <5 ns.
Note: VHT - VHIGH Tes t
VLT - VLOW Test
VIHT - VINPUT HIGH Test
VILT - VINPUT LOW Test
1231 F20.0
TO TESTER
TO DUT
CL
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
21
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
PRODUCT ORDERING INFORMATION
Valid combinations for SST25VF020
SST25VF020-20-4C-SAE SST25VF020-20-4C-QAE
SST25VF020-20-4I-SAE SST25VF020-20-4I-QAE
SST25VF020-20-4E-SAE SST25VF020-20-4E-QAE
Note: Valid combinations are those products in mass production or will be in mass production. Consult your SST sales
representative to confirm availability of valid combinations and to determine availability of new combinations.
Environmental Attribute
E1 = non-Pb
Package Modifier
A = 8 leads or contacts
Package Type
S = SOIC 150 mil body width
Q = WSON
Temperature Range
C = Commercial = 0°C to +70°C
I = Industrial = -40°C to +85°C
E = Extended = -20°C to +85°C
Minimum Endurance
4 = 10,000 cycles
Operating Frequency
20 = 20 MHz
Device Density
020 = 2 Mbit
Voltage
V = 2.7-3.6V
Product Series
25 = Serial Peripheral Interface flash memory
1. Environmental suffix “E” denotes non-Pb solder.
SST non-Pb solder devices are “RoHS Compliant”.
Device Speed Suffix1 Suffix2
SST25VFXXX -XXX -XX-XX X
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22
Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
PACKAGING DIAGRAMS
FIGURE 22: 8-lead Small Outline Integrated Circuit (SOIC) 150 mil body width (4.9mm x 6mm)
SST Package Code: SA
08-soic-5x6-SA-8
Note: 1. Complies with JEDEC publication 95 MS-012 AA dimensions,
although some dimensions may be more stringent.
2. All linear dimensions are in millimeters (max/min).
3. Coplanarity: 0.1 mm
4. Maximum allowable mold flash is 0.15 mm at the package ends and 0.25 mm between leads.
TOP VIEW SIDE VIEW
END VIEW
5.0
4.8
6.20
5.80
4.00
3.80
Pin #1
Identifier
0.51
0.33
1.27 BSC
0.25
0.10
1.75
1.35
4 places
0.25
0.19
1.27
0.40
45°
4 places
1mm
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Data Sheet
2 Mbit SPI Serial Flash
SST25VF020
23
©2006 Silicon Storage Technology, Inc. S71231-07-000 10/06
FIGURE 23: 8-contact Very-very-thin Small Outline No-lead (WSON)
SST Package Code: QA
TABLE 12: Revision History
Number Description Date
00 Initial release of S71231
(2 Mbit and 4 Mbit parts were originally described in data sheet S71192)
Apr 2003
01 Updated Figures 3, 5 - 15: Aligned SI waveform with rising edge of clock Aug 2003
02 Added new 8-SOIC (S2A) package and associated MPNs Oct 2003
03 2004 Data Book
Updated the Package Outline for S2A
Dec 2003
04 Added Extended temperature and associated MPNs Jun 2004
05 Revised Absolute Max. Stress Ratings for Surface Mount Solder Reflow Temp. Nov 2005
06 Updated QA package drawing to revision 9.
Removed leaded parts.
Added footnote to product ordering section.
Jan 2006
07 Removed all references to SST25VF040 due to end of life. New SST25VF040 EOL
data sheet is S71231(04).
Revised Hold Operation, page 5 paragraph 4, to indicate that device returns to
standby mode when CE# is driven active high during a Hold Condition.
Oct 2006
Note: 1. All linear dimensions are in millimeters (max/min).
2. Untoleranced dimensions (shown with box surround)
are nominal target dimensions.
3. The external paddle is electrically connected to the
die back-side and possibly to certain V
SS
leads.
This paddle can be soldered to the PC board;
it is suggested to connect this paddle to the V
SS
of the unit.
Connection of this paddle to any other voltage potential can
result in shorts and/or electrical malfunction of the device.
8-wson-5x6-QA-9.0
4.0
1.27 BSC
Pin #1
0.48
0.35
0.076
3.4
5.00 ± 0.10
6.00 ± 0.10 0.05 Max
0.70
0.50
0.80
0.70
0.80
0.70
Pin #1
Corner
TOP VIEW BOTTOM VIEW
CROSS SECTION
SIDE VIEW
1mm
0.2
Silicon Storage Technology, Inc. • 1171 Sonora Court • Sunnyvale, CA 94086 • Telephone 408-735-9110 • Fax 408-735-9036
www.SuperFlash.com or www.sst.com
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