M24M01-R 1 Mbit serial I²C bus EEPROM Features ■ Compatible with I2C extended addressing ■ Two-wire I2C serial interface supports 1 MHz protocol ■ Single supply voltage: – 1.8 V to 5.5 V ■ Hardware write control ■ Byte and Page Write (up to 256 bytes) ■ Random and Sequential Read modes ■ Self-timed programming cycle ■ Automatic address incrementing ■ Enhanced ESD/Latch-Up protection ■ More than 1 million Write cycles ■ More than 40-year data retention ■ Packages – ECOPACK® (RoHS compliant) November 2007 SO8 (MN) 150 mils width SO8 (MW) 208 mils width Rev 3 1/30 www.st.com 1 Contents M24M01-R Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 Serial Clock (SCL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Serial Data (SDA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Chip Enable (E1, E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4 Write Control (WC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.5 VSS ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.6 Supply voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.6.1 3 4 2/30 2.6.2 Operating supply voltage VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Power-up conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.6.3 Device reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.6.4 Power-down conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Device operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.1 Start condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.2 Stop condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.3 Acknowledge bit (ACK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.4 Data input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.5 Memory addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.6 Write operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.7 Byte Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.8 Page Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.9 ECC (error correction code) and Write cycling . . . . . . . . . . . . . . . . . . . . . 16 3.10 Minimizing system delays by polling on ACK . . . . . . . . . . . . . . . . . . . . . . 18 3.11 Read operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.12 Random Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.13 Current Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.14 Sequential Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.15 Acknowledge in Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Initial delivery state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 M24M01-R Contents 5 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 7 Package mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 8 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3/30 List of tables M24M01-R 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. 4/30 Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Most significant address byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Least significant address byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Input parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 AC characteristics at 400 kHz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 AC characteristics at 1 MHz (preliminary data). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SO8 narrow – 8 lead plastic small outline, 150 mils body width, package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 SO8W – 8 lead plastic small outline, 208 mils body width, package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 M24M01-R 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 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 1MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 I2C bus protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Write mode sequences with WC = 1 (data write inhibited) . . . . . . . . . . . . . . . . . . . . . . . . . 14 Write mode sequences with WC = 0 (data write enabled) . . . . . . . . . . . . . . . . . . . . . . . . . 16 Write cycle polling flowchart using ACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Read mode sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 AC measurement I/O waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 SO8 narrow – 8 lead plastic small outline, 150 mils body width, package outline . . . . . . . 26 SO8W – 8 lead plastic small outline, 208 mils body width, package outline. . . . . . . . . . . . 27 5/30 Description 1 M24M01-R Description The M24M01-R is an I2C-compatible electrically erasable programmable memory (EEPROM) device organized as 128 Kb × 8 bits. The I2C bus is 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 M24M01-R behaves as a slave in the I2C protocol, with all memory operations synchronized by the serial clock. Read and Write operations are generated by the bus master and initiated by a Start condition, followed by the device select code, address bytes and data bytes. Data transfers are terminated by a Stop condition after an Ack for Write, and after a NoAck for Read. 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. In order to meet environmental requirements, ST offers the M24M01-R in ECOPACK® packages. ECOPACK® 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 2 E1-E2 SCL SDA M24M01-R WC VSS AI13415b Table 1. Signal names Signal name 6/30 Function Direction E1, E2 Chip Enable Input SDA Serial Data I/O SCL Serial Clock Input WC Write Control Input VCC Supply voltage VSS Ground M24M01-R Description Figure 2. SO connections M24M01-R NC E1 E2 VSS 1 2 3 4 8 7 6 5 VCC WC SCL SDA AI13416b 1. See Section 7: Package mechanical for package dimensions, and how to identify pin-1. 2. NC = Not Connected internally. 7/30 Signal description M24M01-R 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 5 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 5 indicates how the value of the pull-up resistor can be calculated). 2.3 Chip Enable (E1, E2) These input signals are used to set the value that is to be looked for on the two bits (b2, b1) of the 7-bit device select code. These inputs must be tied to VCC or VSS, to establish the device select code as shown in Figure 3. When not connected (left floating), these inputs are read as low (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. 8/30 M24M01-R 2.5 Signal description VSS ground VSS is the reference for the VCC supply voltage. 2.6 Supply voltage (VCC) 2.6.1 Operating supply voltage VCC 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). 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). 2.6.2 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/µs. 2.6.3 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). When VCC passes over the POR threshold, the device is reset and is in Standby Power mode. In a similar way, during power-down (continuous decrease in VCC), as soon as VCC drops below the Power On Reset threshold voltage, the device stops responding to any instruction sent to it. 2.6.4 Power-down conditions During power-down (continuous decrease in VCC), the device must be in the Standby Power mode (mode reached after decoding a Stop condition, assuming that is there is no internal Write cycle in progress). 9/30 Signal description M24M01-R Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz Figure 4. Bus line pull-up resistor (k ) 100 fC = 400 kHz, tLOW = 1.3 µs Rbus x Cbus time constant must be less than 500 ns VCC 10 Rbus I²C bus master SCL M24xxx SDA 1 10 100 Cbus 1000 Bus line capacitor (pF) ai14796 Bus line pull-up resistor (k ) Figure 5. Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 1MHz 100 VCC fC = 1 MHz, tLOW = 500 ns, time constant Rbus x Cbus must be less than 150 ns Rbus I²C bus master 10 fC = 1 MHz, tLOW = 700 ns, time constant Rbus x Cbus must be less than 270 ns SCL M24xxx SDA Cbus 1 10 100 Bus line capacitor (pF) ai14795 10/30 M24M01-R Signal description Figure 6. I2C bus protocol SCL SDA SDA Input START Condition SCL 1 SDA MSB 2 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 Chip Enable address(2) Device type identifier(1) Device select code A16 RW b7 b6 b5 b4 b3 b2 b1 b0 1 0 1 0 E2 E1 A16 RW 1. The most significant bit, b7, is sent first. 2. E1 and E2 are compared against the respective external pins on the memory device. Table 3. b15 Table 4. b7 Most significant address byte b14 b13 b12 b11 b10 b9 b8 b3 b2 b1 b0 Least significant address byte b6 b5 b4 11/30 Device operation 3 M24M01-R Device operation The device supports the I2C protocol. This is summarized in Figure 6. 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 M24M01-R device is always a slave in all communication. 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 EEPROM 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. 12/30 M24M01-R 3.5 Device operation 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 2-bit Chip Enable “Address” (E2, E1). To address the memory array, the 4-bit device type identifier is 1010b. Up to four memory devices can be connected on a single I2C bus. Each one is given a unique 2-bit code on the Chip Enable (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 (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 Random Address Read Initial sequence Start, device select, RW = 1 Start, device select, RW = 0, Address 1 1 X reStart, device select, RW = 1 Sequential Read 1 X ≥1 Byte Write 0 VIL 1 Start, device select, RW = 0 Page Write 0 VIL ≤256 Start, device select, RW = 0 Similar to Current or Random Address Read 1. X = VIH or VIL. 13/30 Device operation Figure 7. M24M01-R 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 14/30 AI01120d M24M01-R 3.6 Device operation Write operations Following a Start condition the bus master sends a device select code with the R/W bit (RW) reset to 0. The device acknowledges this, as shown in Figure 8, 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 7. Each data byte in the memory has a 17-bit address (the most significant bit b16 is in the device select code and the Least Significant Bits b15-b0 are defined in two address bytes). The most significant byte (Table 3) is sent first, followed by the least significant byte (Table 4). 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 memory 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 8. 3.8 Page Write The Page Write mode allows up to 256 bytes 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, 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 256 bytes 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 6 least significant address bits only) is incremented. The transfer is terminated by the bus master generating a Stop condition. 15/30 Device operation Figure 8. M24M01-R Write mode sequences with WC = 0 (data write enabled) WC ACK ACK Byte addr Byte addr 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 ACK Data in 1 Data in 2 R/W WC (cont'd) ACK Data in N Stop Page Write (cont'd) ACK 3.9 AI01106d ECC (error correction code) and Write cycling The M24M01-R device offers an ECC (error correction code) logic which compares each 4byte word with its six associated EEPROM ECC 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 word), that is, the addressed byte is cycled together with the three other bytes making up the word. It is therefore recommended to write by packets of 4 bytes in order to benefit from the larger amount of Write cycles. The M24M01-R device is qualified at 1 million (1 000 000) Write cycles, using a cycling routine that writes to the device by multiples of 4-byte words. 16/30 M24M01-R Device operation Figure 9. 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 Stop NO StartCondition YES Data for the Write cperation Ddevice select with RW = 1 Continue the Write operation Continue the Random Read operation AI01847d 17/30 Device operation 3.10 M24M01-R 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 11, 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 9, is: ● 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). Figure 10. Read mode sequences ACK Data out Stop Start Dev sel NO ACK R/W ACK Random Address Read Byte addr Dev sel * ACK ACK Data out 1 Data out R/W NO ACK Data out N R/W ACK ACK Byte addr ACK Byte addr ACK Dev sel * Start Start Dev sel * R/W ACK NO ACK Stop Start Dev sel Sequention Random Read ACK Byte addr R/W ACK Sequential Current Read ACK Start Start Dev sel * ACK Stop Current Address Read ACK Data out1 R/W NO ACK Stop Data out N 1. The seven most significant bits of the device select code of a Random Read (in the be identical. 18/30 AI01105d 1st and 4th bytes) must M24M01-R 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 10) but without sending a Stop condition. Then, the bus master sends another Start condition, and repeats the device select code, with the RW bit 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 R/W bit 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 10, 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 10. 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. 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. 19/30 Initial delivery state 4 M24M01-R Initial delivery state The device is delivered with all the memory array bits 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 (1) °C Lead temperature during soldering see note VIO Input or output range –0.50 VCC + 0.6 V VCC Supply voltage –0.50 6.5 V VESD Electrostatic discharge voltage (Human Body model)(2) –3000 3000 V 1. Compliant with JEDEC Std J-STD-020D (for small body, Sn-Pb or Pb assembly), the ST ECOPACK® 7191395 specification, and the European directive on Restrictions on Hazardous Substances (RoHS) 2002/95/EU. 2. AEC-Q100-002 (compliant with JEDEC Std JESD22-A114A, C1=100pF, R1=1500Ω, R2=500Ω) 20/30 M24M01-R 6 DC and AC parameters 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 Symbol VCC TA Table 8. Parameter Min. Max. Unit Supply voltage 1.8 5.5 V Ambient operating temperature –40 85 °C Max. Unit AC measurement conditions Symbol CL Parameter Min. Load capacitance 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 11. AC measurement I/O waveform Input Levels Input and Output Timing Reference Levels 0.8VCC 0.7VCC 0.3VCC 0.2VCC AI00825B Table 9. Input parameters Symbol Parameter(1) Test condition Min. Max. Unit CIN Input capacitance (SDA) 8 pF CIN Input capacitance (other pins) 6 pF ZL ZH Input impedance (WC) VIN < 0.3 VCC 30 kΩ VIN > 0.7VCC 400 kΩ 1. Sampled only, not 100% tested. 21/30 DC and AC parameters Table 10. Symbol M24M01-R DC characteristics Parameter ILI Input leakage current (E1, E2, SCL, SDA) ILO Output leakage current ICC ICC0 ICC1 Max. Unit VIN = VSS or VCC device in Standby mode ±2 µA VOUT = VSS or VCC, SDA in Hi-Z ±2 µA VCC = 1.8 V, fc= 400 kHz (rise/fall time < 50 ns) 0.8 mA VCC = 2.5 V, fc= 400 kHz (rise/fall time < 50 ns) 1 mA VCC = 5.0 V, fc= 400 kHz (rise/fall time < 50 ns) 2 mA 1.8 V < VCC < 5.5 V, fc= 1 MHz (rise/fall time < 50 ns) 2.5 mA Supply current (Write) During tW, 1.8V < VCC < 5.5V 5(1) mA VIN = VSS or VCC, VCC = 1.8 V 1 µA VIN = VSS or VCC, VCC = 2.5 V 2 µA VIN = VSS or VCC, VCC = 5.5 V 3 µA V Standby supply current Input low voltage (SCL, SDA, WC) VIH Input high voltage (SCL, SDA, WC) Output low voltage 1.8 V ≤VCC < 2.5 V –0.45 0.25 VCC 2.5 V ≤VCC ≤5.5 V –0.45 0.3 VCC 1.8 V ≤VCC < 2.5 V 0.75VCC VCC+1 2.5 V ≤VCC ≤5.5 V 0.7VCC VCC+1 V IOL = 0.7 mA, VCC = 1.8 V 0.2 V IOL = 2.1 mA, VCC = 2.5 V 0.4 V IOL = 3.0 mA, VCC = 5.5 V 0.4 V 1. Characterized value, not tested in production. 22/30 Min. Supply current (Read) VIL VOL Test condition (in addition to those in Table 7) M24M01-R DC and AC parameters Table 11. AC characteristics at 400 kHz Test conditions specified in Table 7 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 tXH1XH2(1) tR Input signal rise time 20 300 ns tXL1XL2(1) tF Input signal fall time 20 300 ns tDL1DL2 tF SDA (out) fall time 20 100 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)(3) tAA Clock low to next data valid (access time) 200 900 ns tCHDX(4) 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 Pulse width ignored (input filter on SCL and SDA) tW tNS(5) tWR Write time 1.8 V < VCC < 5.5 V 100 ns 5 ms 1. Values recommended by the I²C-bus Fast-Mode specification. 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. tCLQV is the time (from the falling edge of SCL) required by the SDA bus line to reach 0.8VCC in a compatible way with the I2C specification (which specifies tSU:DAT (min) = 100 ns), assuming that the Rbus × Cbus time constant is less than 500 ns (as specified in Figure 4). 4. For a reStart condition, or following a Write cycle. 5. Characterized only, not tested in production. 23/30 DC and AC parameters Table 12. M24M01-R AC characteristics at 1 MHz (preliminary data) Test conditions specified in Table 7 Symbol Alt. Parameter Min. Max. Unit fC fSCL Clock frequency 0 1 MHz tCHCL tHIGH Clock pulse width high 300 - ns tCLCH tLOW Clock pulse width low 400 - ns tXH1XH2(1) tR Input signal rise time 20 300 ns (1) tF Input signal fall time 20 300 ns (2) tF SDA (out) fall time 20 100 ns tDXCX tSU:DAT Data in setup time 80 - ns tCLDX tHD:DAT Data in hold time 0 - ns tXL1XL2 tDL1DL2 tCLQX tDH Data out hold time 50 - ns tCLQV(3)(4) tAA Clock low to next data valid (access time) 50 500 ns tCHDX(5) tSU:STA Start condition setup time 250 - ns tDLCL tHD:STA Start condition hold time 250 - ns tCHDH tSU:STO Stop condition setup time 250 - ns tDHDL tBUF Time between Stop condition and next Start condition 500 - ns tW tWR Write time - 5 ms Pulse width ignored (input filter on SCL and SDA) - 50 ns tNS(2) 1. Values recommended by the I²C-bus Fast-Mode specification. 2. Characterized only, not tested in production. 3. To avoid spurious Start and Stop conditions, a minimum delay is placed between SCL=1 and the falling or rising edge of SDA. 4. tCLQV is the time (from the falling edge of SCL) required by the SDA bus line to reach 0.8VCC, assuming that the Rbus × Cbus time constant is less than 150 ns (as specified in Figure 4). 5. For a reStart condition, or following a Write cycle. 24/30 M24M01-R DC and AC parameters Figure 12. AC waveforms tXL1XL2 tCHCL tXH1XH2 tCLCH SCL tDLCL tXL1XL2 SDA In tCHDX tCLDX tXH1XH2 Start condition SDA Input SDA tDXCX Change tCHDH tDHDL Start Stop condition condition SCL SDA In tW tCHDH tCHDX Stop condition Write cycle Start condition tCHCL SCL tCLQV SDA Out tCLQX Data valid tDL1DL2 Data valid AI00795e 25/30 Package mechanical 7 M24M01-R Package mechanical Figure 13. SO8 narrow – 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 13. SO8 narrow – 8 lead plastic small outline, 150 mils body width, package mechanical data inches(1) millimeters Symbol Typ Min A Max Typ 1.75 Max 0.0689 A1 0.1 A2 1.25 b 0.28 0.48 0.011 0.0189 c 0.17 0.23 0.0067 0.0091 ccc 0.25 0.0039 0.0098 0.0492 0.1 0.0039 D 4.9 4.8 5 0.1929 0.189 0.1969 E 6 5.8 6.2 0.2362 0.2283 0.2441 E1 3.9 3.8 4 0.1535 0.1496 0.1575 e 1.27 - - 0.05 - - h 0.25 0.5 0.0098 0.0197 k 0° 8° 0° 8° L 0.4 1.27 0.0157 0.05 L1 1.04 0.0409 1. Values in inches are converted from mm and rounded to 4 decimal digits. 26/30 Min M24M01-R Package mechanical Figure 14. 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. 2. The ‘1’ that appears in the top view of the package shows the position of pin 1 and the ‘N’ indicates the total number of pins. Table 14. SO8W – 8 lead plastic small outline, 208 mils body width, package mechanical data inches(1) millimeters Symbol Typ Min A Max Typ Min 2.5 Max 0.0984 A1 0 0.25 0 0.0098 A2 1.51 2 0.0594 0.0787 b 0.4 0.35 0.51 0.0157 0.0138 0.0201 c 0.2 0.1 0.35 0.0079 0.0039 0.0138 CP 0.1 0.0039 D 6.05 0.2382 E 5.02 6.22 0.1976 0.2449 E1 7.62 8.89 0.3 0.35 - - - - k 0° 10° 0° 10° L 0.5 0.8 0.0197 0.0315 N 8 e 1.27 0.05 8 1. Values in inches are converted from mm and rounded to 4 decimal digits. 27/30 Part numbering 8 M24M01-R Part numbering Table 15. Ordering information scheme Example: M24M01 – H R MN 6 T P Device type M24 = I2C serial access EEPROM Device function M01 = 1 Mbit (256 Kb × 8 bits) Clock frequency Blank: fC max = 400 kHz H: fC max = 1 MHz Operating voltage R = VCC = 1.8 V to 5.5 V Package MN = SO8 (150 mils width) MW = SO8 (208 mils width) 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® (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. 28/30 M24M01-R 9 Revision history Revision history Table 16. Document revision history Date Revision 07-Dec-2006 1 Initial release. 2 Document status promoted from Preliminary Data to full Datasheet. Section 2.6: Supply voltage (VCC) updated. Note 1 updated to latest standard revision below Table 6: Absolute maximum ratings. VIL, VIH modified and, rise/fall time corrected in Test conditions in Table 10: DC characteristics. Package values in inches calculated from mm and rounded to 4 decimal digits (note added below package mechanical data tables in Section 7: Package mechanical. 3 1 MHz maximum clock frequency added: – Figure 5: Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 1MHz – Table 12: AC characteristics at 1 MHz (preliminary data) added. tNS moved from Table 9: Input parameters to Table 11: AC characteristics at 400 kHz. Note removed below Table 9. In Table 11, tCH1CH2, tCL1CL2 and tDL1DL2 removed, tXH1XH2, tXL1XL2 added, tDL1DL2 max modified, notes modified. Figure 4: Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz modified. Figure 12: AC waveforms modified. Small text changes. 02-Oct-2007 26-Nov-2007 Changes 29/30 M24M01-R Please Read Carefully: Information in this document is provided solely in connection with ST products. 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