M24512-W M24512-R M24256-BW M24256-BR 512 Kbit and 256 Kbit serial IC bus EEPROM with three Chip Enable lines Features Two-wire I2C serial interface supports the 400 kHz protocol Supply voltage ranges: - 1.8 V to 5.5 V (M24xxx-R) - 2.5 V to 5.5 V (M24xxx-W) Write Control input Byte and Page Write Random and sequential read modes Self-timed programming cycle Automatic address incrementing Enhanced ESD/latch-up protection More than 1 000 000 Write cycles More than 40-year data retention Packages - ECOPACK(R) (RoHS compliant) SO8 (MW) 208 mils width SO8 (MN) 150 mils width TSSOP8 (DW) July 2007 Rev 7 1/32 www.st.com 1 Contents M24512-W, M24512-R, M24256-BW, M24256-BR Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 Serial Clock (SCL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Serial Data (SDA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Chip Enable (E0, E1, E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4 Write Control (WC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.5 Supply voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.5.1 3 4 2/32 2.5.2 Operating supply voltage VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Power-up conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.5.3 Device reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.5.4 Power-down conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Device operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1 Start condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Stop condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 Acknowledge bit (ACK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.4 Data input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.5 Memory addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.6 Write operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.7 Byte Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.8 Page Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.9 ECC (error correction code) and write cycling . . . . . . . . . . . . . . . . . . . . . 15 3.10 Minimizing system delays by polling on ACK . . . . . . . . . . . . . . . . . . . . . . 16 3.11 Read operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.12 Random Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.13 Current Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.14 Sequential Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.15 Acknowledge in Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Initial delivery state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 M24512-W, M24512-R, M24256-BW, M24256-BR Contents 5 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7 Package mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 8 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3/32 List of tables M24512-W, M24512-R, M24256-BW, M24256-BR List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. 4/32 Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Most significant address byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Least significant address byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Operating conditions (M24xxx-W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Operating conditions (M24xxx-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AC test measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Input parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DC characteristics (M24xxx-W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DC characteristics (M24xxx-R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 AC characteristics (M24xxx-W, see Table 7 and Table 9) . . . . . . . . . . . . . . . . . . . . . . . . . 22 AC characteristics (M24xxx-R, see Table 8 and Table 9). . . . . . . . . . . . . . . . . . . . . . . . . . 23 SO8W - 8 lead plastic small outline, 208 mils body width, package mechanical data . . . . 25 SO8N - 8 lead plastic small outline, 150 mils body width, package mechanical data . . . . 26 TSSOP8 - 8 lead thin shrink small outline, package mechanical data. . . . . . . . . . . . . . . . 27 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Available M24256-Bx products (package, voltage range, temperature grade). . . . . . . . . . 29 Available M24512-x products (package, voltage range, temperature grade) . . . . . . . . . . . 29 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 M24512-W, M24512-R, M24256-BW, M24256-BR List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SO and TSSOP connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Maximum RP value versus bus parasitic capacitance (C) for an I2C bus . . . . . . . . . . . . . . . 9 I2C bus protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Write mode sequences with WC = 1 (data write inhibited) . . . . . . . . . . . . . . . . . . . . . . . . . 13 Write Mode sequences with WC = 0 (data write enabled) . . . . . . . . . . . . . . . . . . . . . . . . . 15 Write cycle polling flowchart using ACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Read mode sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 AC test measurement I/O waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SO8W - 8 lead plastic small outline, 208 mils body width, package outline. . . . . . . . . . . . 25 SO8N - 8 lead plastic small outline, 150 mils body width, package outline . . . . . . . . . . . . 26 TSSOP8 - 8 lead thin shrink small outline, package outline . . . . . . . . . . . . . . . . . . . . . . . 27 5/32 Description 1 M24512-W, M24512-R, M24256-BW, M24256-BR Description The M24512-W, M24512-R, M24256-BW and M24256-BR devices are I2C-compatible electrically erasable programmable memories (EEPROM). They are organized as 64 Kb x 8 bits and 32 Kb x 8 bits, respectively. I2C uses a two-wire serial interface, comprising a bidirectional data line and a clock line. The devices carry a built-in 4-bit Device Type Identifier code (1010) in accordance with the I2C bus definition. The device behaves as a slave in the I2C protocol, with all memory operations synchronized by the serial clock. Read and Write operations are initiated by a Start condition, generated by the bus master. The Start condition is followed by a device select code and Read/Write bit (RW) (as described in Table 2), terminated by an acknowledge bit. When writing data to the memory, the device inserts an acknowledge bit during the 9th bit time, following the bus master's 8-bit transmission. When data is read by the bus master, the bus master acknowledges the receipt of the data byte in the same way. Data transfers are terminated by a Stop condition after an Ack for Write, and after a NoAck for Read. In order to meet environmental requirements, ST offers these devices in ECOPACK(R) packages. ECOPACK(R) packages are Lead-free and RoHS compliant. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. Figure 1. Logic diagram VCC 3 E0-E2 SCL M24512-W M24512-R M24256-BW M24256-BR SDA WC VSS AI02275c Table 1. 6/32 Signal names E0, E1, E2 Chip Enable SDA Serial Data SCL Serial Clock WC Write Control VCC Supply Voltage VSS Ground M24512-W, M24512-R, M24256-BW, M24256-BR Figure 2. Description SO and TSSOP connections M24512-W M24512-R M24256-BW M24256-BR E0 E1 E2 VSS 1 2 3 4 8 7 6 5 VCC WC SCL SDA AI04035d 1. See Package mechanical section for package dimensions, and how to identify pin-1. 7/32 Signal description M24512-W, M24512-R, M24256-BW, M24256-BR 2 Signal description 2.1 Serial Clock (SCL) This input signal is used to strobe all data in and out of the device. In applications where this signal is used by slave devices to synchronize the bus to a slower clock, the bus master must have an open drain output, and a pull-up resistor must be connected from Serial Clock (SCL) to VCC. (Figure 4. indicates how the value of the pull-up resistor can be calculated). In most applications, though, this method of synchronization is not employed, and so the pullup resistor is not necessary, provided that the bus master has a push-pull (rather than open drain) output. 2.2 Serial Data (SDA) This bidirectional signal is used to transfer data in or out of the device. It is an open drain output that may be wire-OR'ed with other open drain or open collector signals on the bus. A pull up resistor must be connected from Serial Data (SDA) to VCC. (Figure 4. indicates how the value of the pull-up resistor can be calculated). 2.3 Chip Enable (E0, E1, E2) These input signals are used to set the value that is to be looked for on the three least significant bits (b3, b2, b1) of the 7-bit device select code. These inputs must be tied to VCC or VSS, to establish the device select code. When not connected (left floating), these inputs are read as Low (0,0,0). Figure 3. Device select code VCC VCC M24xxx M24xxx Ei Ei VSS VSS Ai12806 2.4 Write Control (WC) This input signal is useful for protecting the entire contents of the memory from inadvertent write operations. Write operations are disabled to the entire memory array when Write Control (WC) is driven High. When unconnected, the signal is internally read as VIL, and Write operations are allowed. When Write Control (WC) is driven High, Device Select and Address bytes are acknowledged, Data bytes are not acknowledged. 8/32 M24512-W, M24512-R, M24256-BW, M24256-BR 2.5 Supply voltage (VCC) 2.5.1 Operating supply voltage VCC Signal description Prior to selecting the memory and issuing instructions to it, a valid and stable VCC voltage within the specified [VCC(min), VCC(max)] range must be applied (see Table 7 and Table 8). In order to secure a stable DC supply voltage, it is recommended to decouple the VCC line with a suitable capacitor (usually of the order of 10 nF to 100 nF) close to the VCC/VSS package pins. This voltage must remain stable and valid until the end of the transmission of the instruction and, for a Write instruction, until the completion of the internal write cycle (tW). 2.5.2 Power-up conditions When the power supply is turned on, VCC rises from VSS to VCC, the VCC rise time must not vary faster than 1 V/s. 2.5.3 Device reset In order to prevent inadvertent Write operations during power-up, a power on reset (POR) circuit is included. At power-up (continuous rise of VCC), the device does not respond to any instruction until VCC has reached the power on reset threshold voltage (this threshold is lower than the minimum VCC operating voltage defined in Table 7 and Table 8). When VCC passes the POR threshold, the device is reset and is in the Standby Power mode. In a similar way, during power-down (continuous decrease of VCC), as soon as VCC drops below the power on reset threshold voltage, the device stops responding to any instruction sent to it. Power-down conditions During power-down (where VCC decreases continuously), the device must be in the Standby Power mode (mode reached after decoding a Stop condition, assuming that there is no internal Write cycle in progress). Figure 4. Maximum RP value versus bus parasitic capacitance (C) for an I2C bus VCC 20 Maximum RP value (k) 2.5.4 16 RP 12 RP SDA MASTER 8 fc = 100kHz 4 fc = 400kHz C SCL C 0 10 100 1000 C (pF) AI01665b 9/32 Signal description Figure 5. M24512-W, M24512-R, M24256-BW, M24256-BR I2C bus protocol SCL SDA SDA Input START Condition SCL 1 2 SDA MSB SDA Change STOP Condition 3 7 8 9 ACK START Condition SCL 1 SDA MSB 2 3 7 8 9 ACK STOP Condition AI00792B Table 2. Device select code Device type identifier(1) Chip Enable address(2) RW b7 b6 b5 b4 b3 b2 b1 b0 1 0 1 0 E2 E1 E0 RW Device select code 1. The most significant bit, b7, is sent first. 2. E0, E1 and E2 are compared against the respective external pins on the memory device. Table 3. b15 Table 4. b7 10/32 Most significant address byte b14 b13 b12 b11 b10 b9 b8 b3 b2 b1 b0 Least significant address byte b6 b5 b4 M24512-W, M24512-R, M24256-BW, M24256-BR 3 Device operation Device operation The device supports the I2C protocol. This is summarized in Figure 5.. Any device that sends data on to the bus is defined to be a transmitter, and any device that reads the data to be a receiver. The device that controls the data transfer is known as the bus master, and the other as the slave device. A data transfer can only be initiated by the bus master, which will also provide the serial clock for synchronization. The M24512-W, M24512-R, M24256-BW and M24256-BR devices are always slaves in all communications. 3.1 Start condition Start is identified by a falling edge of Serial Data (SDA) while Serial Clock (SCL) is stable in the High state. A Start condition must precede any data transfer command. The device continuously monitors (except during a Write cycle) Serial Data (SDA) and Serial Clock (SCL) for a Start condition, and will not respond unless one is given. 3.2 Stop condition Stop is identified by a rising edge of Serial Data (SDA) while Serial Clock (SCL) is stable and driven High. A Stop condition terminates communication between the device and the bus master. A Read command that is followed by NoAck can be followed by a Stop condition to force the device into the Standby mode. A Stop condition at the end of a Write command triggers the internal Write cycle. 3.3 Acknowledge bit (ACK) The acknowledge bit is used to indicate a successful byte transfer. The bus transmitter, whether it be bus master or slave device, releases Serial Data (SDA) after sending eight bits of data. During the 9th clock pulse period, the receiver pulls Serial Data (SDA) Low to acknowledge the receipt of the eight data bits. 3.4 Data input During data input, the device samples Serial Data (SDA) on the rising edge of Serial Clock (SCL). For correct device operation, Serial Data (SDA) must be stable during the rising edge of Serial Clock (SCL), and the Serial Data (SDA) signal must change only when Serial Clock (SCL) is driven Low. 11/32 Device operation 3.5 M24512-W, M24512-R, M24256-BW, M24256-BR Memory addressing To start communication between the bus master and the slave device, the bus master must initiate a Start condition. Following this, the bus master sends the device select code, shown in Table 2. (on Serial Data (SDA), most significant bit first). The device select code consists of a 4-bit device type identifier, and a 3-bit Chip Enable "Address" (E2, E1, E0). To address the memory array, the 4-bit Device Type Identifier is 1010b. Up to eight memory devices can be connected on a single I2C bus. Each one is given a unique 3-bit code on the Chip Enable (E0, E1, E2) inputs. When the device select code is received, the device only responds if the Chip Enable Address is the same as the value on the Chip Enable (E0, E1, E2) inputs. The 8th bit is the Read/Write bit (RW). This bit is set to 1 for Read and 0 for Write operations. If a match occurs on the Device Select code, the corresponding device gives an acknowledgment on Serial Data (SDA) during the 9th bit time. If the device does not match the Device Select code, it deselects itself from the bus, and goes into Standby mode. Table 5. Operating modes Mode Current Address Read RW bit WC(1) Bytes 1 X 1 0 X Initial sequence Start, Device Select, RW = 1 Start, Device Select, RW = 0, Address Random Address Read 1 X Sequential Read 1 X 1 Byte Write 0 VIL 1 1 re-Start, Device Select, RW = 1 Similar to Current or Random Address Read Start, Device Select, RW = 0 128 for 512 Kbit devices Page Write 1. X = VIH or VIL. 12/32 0 VIL 64 for 256 Kbit devices Start, Device Select, RW = 0 M24512-W, M24512-R, M24256-BW, M24256-BR Figure 6. Device operation Write mode sequences with WC = 1 (data write inhibited) WC ACK BYTE ADDR ACK BYTE ADDR NO ACK DATA IN STOP DEV SEL START BYTE WRITE ACK R/W WC ACK DEV SEL START PAGE WRITE ACK BYTE ADDR ACK BYTE ADDR NO ACK DATA IN 1 DATA IN 2 R/W WC (cont'd) NO ACK DATA IN N STOP PAGE WRITE (cont'd) NO ACK AI01120C 13/32 Device operation 3.6 M24512-W, M24512-R, M24256-BW, M24256-BR Write operations Following a Start condition the bus master sends a device select code with the Read/Write bit (RW) reset to 0. The device acknowledges this, as shown in Figure 7., and waits for two address bytes. The device responds to each address byte with an acknowledge bit, and then waits for the data byte. Writing to the memory may be inhibited if Write Control (WC) is driven High. Any Write instruction with Write Control (WC) driven High (during a period of time from the Start condition until the end of the two address bytes) will not modify the memory contents, and the accompanying data bytes are not acknowledged, as shown in Figure 6.. Each data byte in the memory has a 16-bit (two byte wide) address. The most significant byte (Table 3.) is sent first, followed by the least significant byte (Table 4.). Bits b15 to b0 form the address of the byte in memory. When the bus master generates a Stop condition immediately after the Ack bit (in the "10th bit" time slot), either at the end of a Byte Write or a Page Write, the internal Write cycle is triggered. A Stop condition at any other time slot does not trigger the internal Write cycle. After the Stop condition, the delay tW, and the successful completion of a Write operation, the device's internal address counter is incremented automatically, to point to the next byte address after the last one that was modified. During the internal Write cycle, Serial Data (SDA) is disabled internally, and the device does not respond to any requests. 3.7 Byte Write After the Device Select code and the address bytes, the bus master sends one data byte. If the addressed location is Write-protected, by Write Control (WC) being driven High, the device replies with NoAck, and the location is not modified. If, instead, the addressed location is not Write-protected, the device replies with Ack. The bus master terminates the transfer by generating a Stop condition, as shown in Figure 7. 3.8 Page Write The Page Write mode allows up to 64 bytes (for the M24256-BW and M24256-BR) or 128 bytes (for the M24512-W and M24512-R) to be written in a single Write cycle, provided that they are all located in the same 'row' in the memory: that is, the most significant memory address bits (b15-b6 for the M24256-BW and M24256-BR, and b15-b7 for the M24512-W and M24512-R) are the same. If more bytes are sent than will fit up to the end of the row, a condition known as `roll-over' occurs. This should be avoided, as data starts to become overwritten in an implementation dependent way. The bus master sends from 1 to 64 bytes (for the M24256-BW and M24256-BR) or from 1 to 128 bytes (for the M24512-W and M24512-R) of data, each of which is acknowledged by the device if Write Control (WC) is Low. If Write Control (WC) is High, the contents of the addressed memory location are not modified, and each data byte is followed by a NoAck. After each byte is transferred, the internal byte address counter (the 7 least significant address bits only) is incremented. The transfer is terminated by the bus master generating a Stop condition. 14/32 M24512-W, M24512-R, M24256-BW, M24256-BR 3.9 Device operation ECC (error correction code) and write cycling The M24512-W, M24512-R, M24256-BW and M24256-BR devices offer an ECC (error correction code) logic which compares each 4-byte word with its six associated ECC EEPROM bits. As a result, if a single bit out of 4 bytes of data happens to be erroneous during a Read operation, the ECC detects it and replaces it by the correct value. The read reliability is therefore much improved by the use of this feature. Note however that even if a single byte has to be written, 4 bytes are internally modified (plus the ECC bits), that is, the addressed byte is cycled together with the other three bytes making up the word. It is therefore recommended to write by word (4 bytes) in order to benefit from the larger amount of Write cycles. The M24512-W, M24512-R, M24256-BW and M24256-BR devices are qualified at 1 million (1 000 000) Write cycles, using a cycling routine that writes to the device by multiples of 4bytes. Note that the M24512-W and M24512-R in SO8 Wide package (MW) are offered with either the previous die qualified at 100.000 Write cycles or the new die (qualified at 1 Million Write cycles). The two dice are distinguished by their respective process letter: "V" for the previous die and " A" for the new die. Please contact your nearest ST sales office for more information. Figure 7. Write Mode sequences with WC = 0 (data write enabled) WC ACK ACK BYTE ADDR ACK BYTE ADDR ACK DATA IN STOP DEV SEL START BYTE WRITE R/W WC ACK PAGE WRITE DEV SEL START ACK BYTE ADDR ACK BYTE ADDR ACK DATA IN 1 DATA IN 2 R/W WC (cont'd) ACK PAGE WRITE (cont'd) ACK DATA IN N STOP Caution: AI01106C 15/32 Device operation Figure 8. M24512-W, M24512-R, M24256-BW, M24256-BR Write cycle polling flowchart using ACK WRITE Cycle in Progress START Condition DEVICE SELECT with RW = 0 NO First byte of instruction with RW = 0 already decoded by the device ACK Returned YES NO Next Operation is Addressing the Memory YES Send Address and Receive ACK ReSTART NO STOP START Condition YES DATA for the WRITE Operation DEVICE SELECT with RW = 1 Continue the WRITE Operation Continue the Random READ Operation AI01847C 3.10 Minimizing system delays by polling on ACK During the internal Write cycle, the device disconnects itself from the bus, and writes a copy of the data from its internal latches to the memory cells. The maximum Write time (tw) is shown in Table 13., but the typical time is shorter. To make use of this, a polling sequence can be used by the bus master. The sequence, as shown in Figure 8., is: 16/32 Initial condition: a Write cycle is in progress. Step 1: the bus master issues a Start condition followed by a device select code (the first byte of the new instruction). Step 2: if the device is busy with the internal Write cycle, no Ack will be returned and the bus master goes back to Step 1. If the device has terminated the internal Write cycle, it responds with an Ack, indicating that the device is ready to receive the second part of the instruction (the first byte of this instruction having been sent during Step 1). M24512-W, M24512-R, M24256-BW, M24256-BR 3.11 Device operation Read operations Read operations are performed independently of the state of the Write Control (WC) signal. After the successful completion of a Read operation, the device's internal address counter is incremented by one, to point to the next byte address. 3.12 Random Address Read A dummy Write is first performed to load the address into this address counter (as shown in Figure 9.) but without sending a Stop condition. Then, the bus master sends another Start condition, and repeats the device select code, with the Read/Write bit (RW) set to 1. The device acknowledges this, and outputs the contents of the addressed byte. The bus master must not acknowledge the byte, and terminates the transfer with a Stop condition. 3.13 Current Address Read For the Current Address Read operation, following a Start condition, the bus master only sends a device select code with the Read/Write bit (RW) set to 1. The device acknowledges this, and outputs the byte addressed by the internal address counter. The counter is then incremented. The bus master terminates the transfer with a Stop condition, as shown in Figure 9., without acknowledging the byte. 3.14 Sequential Read This operation can be used after a Current Address Read or a Random Address Read. The bus master does acknowledge the data byte output, and sends additional clock pulses so that the device continues to output the next byte in sequence. To terminate the stream of bytes, the bus master must not acknowledge the last byte, and must generate a Stop condition, as shown in Figure 9. The output data comes from consecutive addresses, with the internal address counter automatically incremented after each byte output. After the last memory address, the address counter `rolls-over', and the device continues to output data from memory address 00h. 17/32 Device operation Read mode sequences ACK CURRENT ADDRESS READ DATA OUT STOP START DEV SEL NO ACK R/W ACK START DEV SEL * ACK BYTE ADDR ACK DEV SEL * ACK DATA OUT 1 ACK ACK NO ACK DATA OUT N BYTE ADDR ACK BYTE ADDR ACK DEV SEL * START START ACK R/W ACK DATA OUT R/W R/W DEV SEL * NO ACK STOP START DEV SEL SEQUENTIAL RANDOM READ BYTE ADDR R/W ACK SEQUENTIAL CURRENT READ ACK START RANDOM ADDRESS READ STOP Figure 9. M24512-W, M24512-R, M24256-BW, M24256-BR ACK DATA OUT 1 R/W NO ACK STOP DATA OUT N AI01105C 1. The seven most significant bits of the device select code of a Random Read (in the 1st and 4th bytes) must be identical. 3.15 Acknowledge in Read mode For all Read commands, the device waits, after each byte read, for an acknowledgment during the 9th bit time. If the bus master does not drive Serial Data (SDA) Low during this time, the device terminates the data transfer and switches to its Standby mode. 18/32 M24512-W, M24512-R, M24256-BW, M24256-BR 4 Initial delivery state Initial delivery state The device is delivered with all bits in the memory array set to 1 (each byte contains FFh). 5 Maximum rating Stressing the device outside the ratings listed in Table 6 may cause permanent damage to the device. These are stress ratings only, and operation of the device at these, or any other conditions outside those indicated in the operating sections of this specification, is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 6. Absolute maximum ratings Symbol TA TSTG TLEAD Parameter Min. Max. Unit Ambient operating temperature -40 130 C Storage temperature -65 150 C Lead temperature during soldering See note (1) C VIO Input or output range -0.50 6.5 V VCC Supply voltage -0.50 6.5 V VESD Electrostatic discharge voltage (human body model) (2) -4000 4000 V ECOPACK(R) 1. Compliant with JEDEC Std J-STD-020C (for small body, Sn-Pb or Pb assembly), the ST 7191395 specification, and the European directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS) 2002/95/EC. 2. AEC-Q100-002 (compliant with JEDEC Std JESD22-A114D, C1 = 100 pF, R1 = 1500 , R2 = 500 ) 19/32 DC and AC parameters 6 M24512-W, M24512-R, M24256-BW, M24256-BR DC and AC parameters This section summarizes the operating and measurement conditions, and the dc and ac characteristics of the device. The parameters in the dc and ac characteristic tables that follow are derived from tests performed under the measurement conditions summarized in the relevant tables. Designers should check that the operating conditions in their circuit match the measurement conditions when relying on the quoted parameters. Table 7. Operating conditions (M24xxx-W) Symbol VCC TA Table 8. Parameter Min. Max. Unit Supply voltage 2.5 5.5 V Ambient operating temperature -40 85 C Min. Max. Unit Supply voltage 1.8 5.5 V Ambient operating temperature -40 85 C Operating conditions (M24xxx-R) Symbol VCC TA Table 9. Parameter AC test measurement conditions Symbol CL Parameter Min. Load capacitance Max. 100 Input rise and fall times pF 50 ns Input levels 0.2VCC to 0.8VCC V Input and output timing reference levels 0.3VCC to 0.7VCC V Figure 10. AC test measurement I/O waveform Input Levels 0.8VCC 0.2VCC Input and Output Timing Reference Levels 0.7VCC 0.3VCC AI00825B 20/32 Unit M24512-W, M24512-R, M24256-BW, M24256-BR Table 10. Symbol DC and AC parameters Input parameters Parameter(1),(2) Test condition Min. Max. Unit CIN Input capacitance (SDA) 8 pF CIN Input capacitance (other pins) 6 pF ZL(3) Input impedance (E2, E1, E0, WC) VIN < 0.3VCC 30 k ZH(3) Input impedance (E2, E1, E0, WC) VIN > 0.7VCC 500 k Pulse width ignored (Input filter on SCL and SDA) Single glitch tNS 100 ns 1. TA = 25 C, f = 400 kHz 2. Sampled only, not 100% tested. 3. E2,E1,E0: Input impedance when the memory is selected (after a Start condition). Table 11. Symbol DC characteristics (M24xxx-W) Parameter Test conditions (see Table 7 and Table 9) Min. Max. Unit ILI Input leakage current (SCL, SDA, E0, E1, E2) VIN = VSS or VCC device in Standby mode 2 A ILO Output leakage current VOUT = VSS or VCC, SDA in Hi-Z 2 A VCC = 2.5V, fc=400 kHz (rise/fall time < 50 ns) 1 mA VCC = 5.5 V, fc=400 kHz (rise/fall time < 50 ns) 2 mA During tW, 2.5 V < VCC < 5.5 V 5(1) mA VIN = VSS or VCC, VCC = 2.5 V 2 A VIN = VSS or VCC, VCC = 5.5 V 5 A ICC Supply current (Read) ICC0 Supply current (Write) ICC1 Standby supply current VIL Input low voltage (SCL, SDA, WC) -0.45 0.3VCC V VIH Input high voltage (SCL, SDA, WC) 0.7VCC VCC+0.6 V VOL Output low voltage 0.4 V IOL = 2.1 mA, VCC = 2.5 V 1. Characterized value, not tested in production. 21/32 DC and AC parameters Table 12. M24512-W, M24512-R, M24256-BW, M24256-BR DC characteristics (M24xxx-R) Symbol Parameter Test conditions (see Table 8 and Table 9) ILI Input leakage current (SCL, SDA, E2, E1, E0) ILO Min. Max. Unit VIN = VSS or VCC device in Standby mode 2 A Output leakage current VOUT = VSS or VCC, SDA in Hi-Z 2 A ICC Supply current (Read) VCC =1.8 V, fc = 400 kHz (rise/fall time < 50 ns) 1 mA ICC0 Supply current (Write) During tW, 1.8 V < VCC < 5.5 V 5(1) mA ICC1 Standby supply current VIN = VSS or VCC, VCC = 1.8 V 2 A VIL Input low voltage (SCL, SDA, WC) -0.45 0.3 VCC V VIH Input high voltage (SCL, SDA, WC) 0.7VCC VCC+0.6 V VOL Output low voltage 0.2 V IOL = 0.7 mA, VCC = 1.8 V 1. Characterized value, not tested in production. Table 13. AC characteristics (M24xxx-W, see Table 7 and Table 9) Symbol Alt. Parameter Min. Max. Unit fC fSCL Clock frequency 400 kHz tCHCL tHIGH Clock pulse width high 600 ns tCLCH tLOW Clock pulse width low 1300 ns tCH1CH2 tR Clock rise time 300 ns tCL1CL2 tF Clock fall time 300 ns tDH1DH2(1) tR SDA rise time 20 300 ns tDL1DL2(1) tF SDA fall time 20 300 ns tDXCX tSU:DAT Data in set up time 100 ns tCLDX tHD:DAT Data in hold time 0 ns tCLQX tDH Data out hold time 200 ns tCLQV(2) tCHDX(3) tAA Clock low to next data valid (access time) 200 tSU:STA Start condition set up time 600 ns tDLCL tHD:STA Start condition hold time 600 ns tCHDH tSU:STO Stop condition set up time 600 ns tDHDL tBUF Time between Stop condition and next Start condition 1300 ns tW tWR Write time 900 5 ns ms 1. Sampled only, not 100% tested. 2. To avoid spurious Start and Stop conditions, a minimum delay is placed between SCL=1 and the falling or rising edge of SDA. 3. For a re-Start condition, or following a Write cycle. 22/32 M24512-W, M24512-R, M24256-BW, M24256-BR Table 14. DC and AC parameters AC characteristics (M24xxx-R, see Table 8 and Table 9) Symbol Alt. Parameter Min. Max. Unit fC fSCL Clock frequency 400 kHz tCHCL tHIGH Clock pulse width high 600 ns tCLCH tLOW Clock pulse width low 1300 ns tDL1DL2 (1) tF tDXCX tSU:DAT tCLDX tHD:DAT Data in hold time SDA fall time 20 300 ns Data in set up time 100 ns 0 ns ns tCLQX tDH Data out hold time 200 tCLQV(2) tAA Clock low to next data valid (access time) 200 tCHDX(3) tSU:STA Start condition setup time 600 ns 900 ns tDLCL tHD:STA Start condition hold time 600 ns tCHDH tSU:STO Stop condition setup time 600 ns 1300 ns tDHDL tBUF Time between Stop condition and next Start condition tW tWR Write time 10 ms 1. Sampled only, not 100% tested. 2. To avoid spurious Start and Stop conditions, a minimum delay is placed between SCL=1 and the falling or rising edge of SDA. 3. For a re-Start condition, or following a Write cycle. 23/32 DC and AC parameters M24512-W, M24512-R, M24256-BW, M24256-BR Figure 11. AC waveforms tCHCL tCLCH SCL tDLCL SDA In tCHDX tCLDX START Condition SDA Input SDA tDXCX Change tCHDH tDHDL START STOP Condition Condition SCL SDA In tCHDH tW STOP Condition Write Cycle tCHDX START Condition SCL tCLQV SDA Out tCLQX Data Valid AI00795C 24/32 M24512-W, M24512-R, M24256-BW, M24256-BR 7 Package mechanical Package mechanical Figure 12. SO8W - 8 lead plastic small outline, 208 mils body width, package outline A2 A c b CP e D N E E1 1 A1 k L 6L_ME 1. Drawing is not to scale. Table 15. SO8W - 8 lead plastic small outline, 208 mils body width, package mechanical data millimeters inches Symbol Typ Min A Max Typ Min 2.50 Max 0.098 A1 0.00 0.25 0.000 0.010 A2 1.51 2.00 0.059 0.079 b 0.40 0.35 0.51 0.016 0.014 0.020 c 0.20 0.10 0.35 0.008 0.004 0.014 CP 0.10 0.004 D 6.05 0.238 E 5.02 6.22 0.198 0.245 E1 7.62 8.89 0.300 0.350 - - - - k 0 10 0 10 L 0.50 0.80 0.020 0.031 N 8 e 1.27 0.050 8 25/32 Package mechanical M24512-W, M24512-R, M24256-BW, M24256-BR Figure 13. SO8N - 8 lead plastic small outline, 150 mils body width, package outline h x 45 A2 A c ccc b e 0.25 mm GAUGE PLANE D k 8 E1 E 1 L A1 L1 SO-A 1. Drawing is not to scale. Table 16. SO8N - 8 lead plastic small outline, 150 mils body width, package mechanical data millimeters inches Symbol Typ Min A Typ Min 1.75 Max 0.069 A1 0.10 A2 1.25 b 0.28 0.48 0.011 0.019 c 0.17 0.23 0.007 0.009 ccc 0.25 0.004 0.010 0.049 0.10 0.004 D 4.90 4.80 5.00 0.193 0.189 0.197 E 6.00 5.80 6.20 0.236 0.228 0.244 E1 3.90 3.80 4.00 0.154 0.150 0.157 e 1.27 - - 0.050 - - h 0.25 0.50 0.010 0.020 k 0 8 0 8 L 0.40 1.27 0.016 0.050 L1 26/32 Max 1.04 0.041 M24512-W, M24512-R, M24256-BW, M24256-BR Package mechanical Figure 14. TSSOP8 - 8 lead thin shrink small outline, package outline D 8 5 c E1 1 E 4 A1 A L A2 L1 CP b e TSSOP8AM 1. Drawing is not to scale. Table 17. TSSOP8 - 8 lead thin shrink small outline, package mechanical data millimeters inches Symbol Typ Min A Max Min 1.200 A1 0.050 0.150 0.800 1.050 b 0.190 c 0.090 A2 Typ 1.000 CP Max 0.0472 0.0020 0.0059 0.0315 0.0413 0.300 0.0075 0.0118 0.200 0.0035 0.0079 0.0394 0.100 0.0039 D 3.000 2.900 3.100 0.1181 0.1142 0.1220 e 0.650 - - 0.0256 - - E 6.400 6.200 6.600 0.2520 0.2441 0.2598 E1 4.400 4.300 4.500 0.1732 0.1693 0.1772 L 0.600 0.450 0.750 0.0236 0.0177 0.0295 L1 1.000 0 8 0.0394 0 N 8 8 8 27/32 Part numbering 8 M24512-W, M24512-R, M24256-BW, M24256-BR Part numbering Table 18. Ordering information scheme Example: M24512- W MW 6 T P Device type M24 = I2C serial access EEPROM Device function 512- = 512 Kbit (64 Kb x 8) 256-B = 256 Kbit (32 Kb x 8) Operating voltage W = VCC = 2.5 to 5.5 V R = VCC = 1.8 to 5.5 V Package MW = SO8 (208 mils width) MN = SO8 (150 mils body width) DW = TSSOP8 Device grade 6 = Industrial temperature range, -40 to 85 C. Device tested with standard test flow Option blank = standard packing T = tape and reel packing Plating technology P or G = ECOPACK(R) (RoHS compliant) For a list of available options (speed, package, etc.) or for further information on any aspect of this device, please contact your nearest ST sales office. The category of second-level interconnect is marked on the package and on the inner box label, in compliance with JEDEC standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. 28/32 M24512-W, M24512-R, M24256-BW, M24256-BR Table 19. Part numbering Available M24256-Bx products (package, voltage range, temperature grade) M24256-BW 2.5 V to 5.5 V Package M24256-BR 1.8 V to 5.5 V SO8N (MN) Range 6 Range 6 SO8W (MW) Range 6 - TSSOP (DW) Range 6 Range 6 Table 20. Available M24512-x products (package, voltage range, temperature grade) M24512-W 2.5 V to 5.5 V Package M24512-R 1.8 V to 5.5 V SO8N (MN) Range 6 Range 6 SO8W (MW) Range 6 - TSSOP (DW) Range 6 Range 6 29/32 Revision history 9 Revision history Table 21. Date Document revision history Revision Changes 29-Jan-2001 1.1 Lead Soldering Temperature in the Absolute Maximum Ratings table amended Write Cycle Polling Flow Chart using ACK illustration updated LGA8 and SO8(wide) packages added References to PSDIP8 changed to PDIP8, and Package Mechanical data updated 10-Apr-2001 1.2 LGA8 Package Mechanical data and illustration updated SO16 package removed 16-Jul-2001 1.3 LGA8 Package given the designator "LA" 02-Oct-2001 1.4 LGA8 Package mechanical data updated 13-Dec-2001 1.5 Document becomes Preliminary Data Test conditions for ILI, ILO, ZL and ZH made more precise VIL and VIH values unified. tNS value changed 12-Jun-2001 1.6 Document promoted to Full Datasheet 22-Oct-2003 2.0 Table of contents, and Pb-free options added. Minor wording changes in Summary Description, Power-On Reset, Memory Addressing, Write Operations, Read Operations. VIL(min) improved to -0.45V. 3.0 LGA8 package is Not for New Design. 5V and -S supply ranges, and Device Grade 5 removed. Absolute Maximum Ratings for VIO(min) and VCC(min) changed. Soldering temperature information clarified for RoHS compliant devices. Device grade information clarified. AEC-Q100-002 compliance. VIL specification unified for SDA, SCL and WC 4.0 Initial delivery state is FFh (not necessarily the same as Erased). LGA package removed, TSSOP8 and SO8N packages added (see Package mechanical section and <Blue>Table 18., Ordering information scheme). Voltage range R (1.8V to 5.5V) also offered. Minor wording changes. ZL Test Conditions modified in <Blue>Table 10., Input parameters and Note 3. added. ICC and ICC1 values for VCC = 5.5V added to <Blue>Table 11., DC characteristics (M24xxx-W). Note added to <Blue>Table 11., DC characteristics (M24xxx-W). Power On Reset paragraph specified. tW max value modified in <Blue>Table 13., AC characteristics (M24xxxW, see Table 7 and Table 9) and note 4 added. Plating technology changed in <Blue>Table 18., Ordering information scheme. Resistance and capacitance renamed in <Blue>Figure 4., Maximum RP value versus bus parasitic capacitance (C) for an I2C bus. 02-Sep-2004 22-Feb-2005 30/32 M24512-W, M24512-R, M24256-BW, M24256-BR M24512-W, M24512-R, M24256-BW, M24256-BR Table 21. Document revision history (continued) Date 05-May-2006 16-Oct-2006 02-Jul-2007 Revision history Revision Changes 5 Power On Reset paragraph replaced by Section 2.5: Supply voltage (VCC). Figure 3: Device select code added. ECC (error correction code) and write cycling added and specified at 1 Million cycles. ICC0 added and ICC1 specified over the whole voltage range in Table 11 and Table 12. PDIP8 package removed. Packages are ECOPACK(R) compliant. Small text changes. 6 M24256-BW and M24256-BR part numbers added. Section 3.9: ECC (error correction code) and write cycling updated. ICC and ICC1 modified in Table 12: DC characteristics (M24xxx-R). tW modified in Table 13: AC characteristics (M24xxx-W, see Table 7 and Table 9). SO8Narrow package specifications updated (see Table 16 and Figure 13). Blank option removed from below Plating technology in Table 18: Ordering information scheme. 7 Section 2.5: Supply voltage (VCC) modified. Section 3.9: ECC (error correction code) and write cycling modified. JEDEC standard and European directive references corrected below Table 6: Absolute maximum ratings. Rise/fall time conditions modified for ICC and VIH max modified in Table 11: DC characteristics (M24xxx-W) and Table 12: DC characteristics (M24xxx-R) Note 1 removed from Table 11: DC characteristics (M24xxx-W). SO8W package specifications modified in Section 7: Package mechanical. Table 19: Available M24256-Bx products (package, voltage range, temperature grade) and Table 20: Available M24512-x products (package, voltage range, temperature grade) added. 31/32 M24512-W, M24512-R, M24256-BW, M24256-BR Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. 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