M24M02-A125 Automotive 2-Mbit serial I²C bus EEPROM with 1 MHz clock Datasheet - production data Features • Compatible with all I2C bus modes – 1 MHz – 400 kHz – 100 kHz SO8 (MN) 150 mil width • Memory array – 2 Mbit (256 Kbyte) of EEPROM – Page size: 256 byte – Additional Write lockable page (Identification page) • Extended temperature and voltage ranges – -40 °C to 125 °C; 2.5 V to 5.5 V • Schmitt trigger inputs for noise filtering. • Short Write cycle time – Byte Write within 5 ms – Page Write within 5 ms • Write cycle endurance – 4 million Write cycles at 25 °C – 1.2 million Write cycles at 85 °C – 100 k Write cycles at 125 °C • Data retention – 100 years at 25 °C • ESD protection (Human Body Model) – 3000 V • Packages – RoHS compliant and halogen-free (ECOPACK2®) September 2015 This is information on a product in full production. DocID027947 Rev 2 1/38 www.st.com Contents M24M02-A125 Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 4 2.1 Serial Clock (SCL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 Serial Data (SDA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Chip Enable (E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4 Write Control (WC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.5 VSS (ground) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.6 Supply voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Device operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 Start condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.2 Stop condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.3 Data input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.4 Acknowledge bit (ACK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.5 Device addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.6 Identification page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.1 4.2 2/38 Write operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.1.1 Byte Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.1.2 Page Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.1.3 Write Identification Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.1.4 Lock Identification Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.1.5 Minimizing Write delays by polling on ACK . . . . . . . . . . . . . . . . . . . . . . 18 Read operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.2.1 Random Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.2.2 Current Address Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.3 Sequential Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.4 Read Identification Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.5 Read the lock status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.6 Acknowledge in Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 DocID027947 Rev 2 M24M02-A125 5 Contents Application design recommendations . . . . . . . . . . . . . . . . . . . . . . . . . 23 5.1 5.2 Supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5.1.1 Operating supply voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5.1.2 Power-up conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5.1.3 Power-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Cycling with Error Correction Code (ECC) . . . . . . . . . . . . . . . . . . . . . . . . 24 6 Delivery state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 8 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 9.1 SO8N package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 10 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 DocID027947 Rev 2 3/38 3 List of tables M24M02-A125 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. 4/38 Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Address significant bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Device identification code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Cycling performance by groups of 4 byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Operating conditions (voltage range W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Input parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 400 kHz AC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1 MHz AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 SO8N – 8 lead plastic small outline, 150 mils body width, package data . . . . . . . . . . . . . . 34 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 DocID027947 Rev 2 M24M02-A125 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. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8-pin package connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Device select code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 I2C bus protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Write mode sequences with WC = 0 (data write enabled) . . . . . . . . . . . . . . . . . . . . . . . . . 16 Write mode sequences with WC = 1 (data write inhibited) . . . . . . . . . . . . . . . . . . . . . . . . . 17 Write cycle polling flowchart using ACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Read mode sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AC measurement I/O waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Maximum Rbus value versus bus parasitic capacitance Cbus) for an I2C bus at maximum frequency fC = 1MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 SO8N – 8 lead plastic small outline, 150 mils body width, package outline . . . . . . . . . . . . 33 DocID027947 Rev 2 5/38 5 Description 1 M24M02-A125 Description The M24M02-A125 is a 2-Mbit serial EEPROM Automotive grade device operating up to 125 °C. The M24M02-A125 is compliant with the very high level of reliability defined by the Automotive standard AEC-Q100 grade 1. The device is accessed by a simple serial I2C compatible interface running up to 1 MHz. The memory array is based on advanced true EEPROM technology (Electrically Erasable PROgrammable Memory). The M24M02-A125 is a byte-alterable memory (256 K × 8 bits) organized as 1024 pages of 256 byte in which the data integrity is significantly improved with an embedded Error Correction Code logic. The M24M02-A125 offers an additional Identification Page (256 byte) in which the ST device identification can be read. This page can also be used to store sensitive application parameters which can be later permanently locked in read-only mode. Figure 1. Logic diagram :& ( +LJKYROWDJH JHQHUDWRU &RQWUROORJLF 6&/ 6'$ ,2VKLIWUHJLVWHU 'DWD UHJLVWHU <GHFRGHU $GGUHVVUHJLVWHU DQGFRXQWHU SDJH ,GHQWLILFDWLRQSDJH ;GHFRGHU 06Y9 6/38 DocID027947 Rev 2 M24M02-A125 Description Table 1. Signal names Signal name Function Direction E2 Chip Enable Input SDA Serial Data I/O SCL Serial Clock Input WC Write Control Input VCC Supply voltage - VSS Ground - Figure 2. 8-pin package connections $5 6 ## $5 7# % 3#, 6 33 3$! !)V 1. DU: Don't Use (if connected, must be connected to VSS) 2. See Section 9: Package mechanical data for package dimensions, and how to identify pin 1. DocID027947 Rev 2 7/38 37 Signal description M24M02-A125 2 Signal description 2.1 Serial Clock (SCL) The signal applied on this input is used to strobe the data available on SDA(in) and to output the data on SDA(out). 2.2 Serial Data (SDA) SDA is an input/output used to transfer data in or out of the device. SDA(out) 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 between SDA and VCC (Figure 10 indicates how to calculate the value of the pull-up resistor). 2.3 Chip Enable (E2) This input signal is used to set the value that is to be looked for on the bit b3 of the 7-bit device select code (see Table 2). This input must be tied to VCC or VSS, as shown in Figure 3. When not connected (left floating), this input is read as low (0). Figure 3. Device select code 6## 6## -XXX -XXX %I %I 633 633 !I 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. Write operations are enabled when Write Control (WC) is either driven low or left floating. When Write Control (WC) is driven high, device select and address bytes are acknowledged, Data bytes are not acknowledged. 8/38 DocID027947 Rev 2 M24M02-A125 2.5 Signal description VSS (ground) VSS is the reference for the VCC supply voltage. 2.6 Supply voltage (VCC) VCC is the supply voltage pin. DocID027947 Rev 2 9/38 37 Device operation 3 M24M02-A125 Device operation The device supports the I2C protocol (see Figure 4). The I2C bus is controlled by the bus master and the device is always a slave in all communications. The device (bus master or a slave) that sends data on to the bus is defined as a transmitter; the device (bus master or a slave) is defined as a receiver when reading the data. Figure 4. I2C bus protocol 3#, 3$! 3$! )NPUT 34!24 #ONDITION 3#, 3$! -3" 3$! #HANGE 34/0 #ONDITION !#+ 34!24 #ONDITION 3#, 3$! -3" !#+ 34/0 #ONDITION !)" 10/38 DocID027947 Rev 2 M24M02-A125 3.1 Device operation 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 instruction. The device continuously monitors (except during a Write cycle) Serial Data (SDA) and Serial Clock (SCL) for a Start condition. 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 Stop condition at the end of a Write instruction triggers the internal Write cycle. 3.3 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. 3.4 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. DocID027947 Rev 2 11/38 37 Device operation 3.5 M24M02-A125 Device 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, as shown in Table 2. The device select code consists of a 4-bit device type identifier and a one bit Chip Enable address (E2). A device select code handling any value other than 1010b (to select the memory) or 1011b (to select the Identification page) is not acknowledged by the memory device. Two memory devices can be connected on a single I2C bus. Each one is given a unique 1bit code on the Chip Enable (E2) input. When the device select code is received, the memory device only responds if the Chip Enable Address is the same as the value decoded on the E2 input. The 8th bit is the Read/Write bit (RW). This bit is set to 1 for Read and 0 for Write operations. Table 2. Device select code Device type identifier(1) When accessing the memory When accessing the Identification page b7 b6 b5 Chip Enable address(2) b4 b3 MSB Address bit RW b2 b1 b0 (2) 1 0 1 0 E2 A17 A16 RW 1 0 1 1 E2(2) X(3) X(3) RW 1. The most significant bit, b7, is sent first. 2. E2 bit is compared with the value read on input pin E2. 3. X = don’t care. If a match occurs on the device select code, the corresponding memory device gives an acknowledgment on Serial Data (SDA) during the 9th bit time. If the memory device does not match the device select code, it deselects itself from the bus, and goes into Standby mode. Once the memory device has acknowledged the device select code (Table 2), the memory device waits for the master to send two address bytes (most significant address byte sent first, followed by the least significant address byte (Table 3). The memory device responds to each address byte with an acknowledge bit. Note: A: significant address bit. X: bit is Don’t Care. 12/38 DocID027947 Rev 2 M24M02-A125 Device operation Table 3. Address significant bits Memory(1) (2) Identification page (Device type identifier = 1010b) (Device type identifier = 1011b) Random Address Read Write Read Identification page Write Identification page Lock Identification page Read lock status b17 A17 A17 X X X X Device Select bit 1 b16 A16 A16 X X X X b15 A15 A15 X X X X b14 A14 A14 X X X X b13 A13 A13 X X X X b12 A12 A12 X X X X b11 A11 A11 X X X X b10 A10 A10 X 0 1 0 b9 A9 A9 X X X X b8 A8 A8 X X X X b7 A7 A7 A7 A7 X X b6 A6 A6 A6 A6 X X b5 A5 A5 A5 A5 X X b4 A4 A4 A4 A4 X X b3 A3 A3 A3 A3 X X b2 A2 A2 A2 A2 X X b1 A1 A1 A1 A1 X X b0 A0 A0 A0 A0 X X Lower address byte Upper address byte Device Select bit 2 1. A: significant address bit. 2. X: bit is Don’t Care. DocID027947 Rev 2 13/38 37 Device operation 3.6 M24M02-A125 Identification page The M24M02-A125 offers an Identification Page (256 byte) in addition to the 2 Mb memory. The Identification page contains two fields: Note: • Device identification code: the first three bytes are programmed by STMicroelectronics with the Device identification code, as shown in Table 4. • Application parameters: the bytes after the Device identification code are available for application specific data. If the end application does not need to read the Device identification code, this field can be overwritten and used to store application-specific data. Once the application-specific data are written in the Identification page, the whole Identification page should be permanently locked in Read-only mode. The instructions Read, Write and Lock Identification Page are detailed in Section 4: Instructions. Table 4. Device identification code Address in Identification page 00h 14/38 Content ST manufacturer code 2C family code 01h I 02h Memory density code DocID027947 Rev 2 Value 20h E0h 12h (2048 Kbit) M24M02-A125 4 Instructions 4.1 Write operations Instructions For a Write operation, the bus master sends a Start condition followed by a device select code with the R/W bit reset to 0. The device acknowledges this, as shown in Figure 5, and waits for the master to send two address bytes (most significant address byte sent first, followed by the least significant address byte (Table 3). The device responds to each address byte with an acknowledge bit, and then waits for the data byte. The 256 Kbyte (2 Mb) are addressed with 18 address bits, the 16 lower address bits being defined by the two address bytes and the most significant address bits (A17, A16) being included in the Device Select code (see Table 2). When the bus master generates a Stop condition immediately after a data byte Ack bit (in the “10th bit” time slot), either at the end of a Byte Write or a Page Write, the internal Write cycle tW is then triggered. A Stop condition at any other time slot does not trigger the internal Write cycle. During the internal Write cycle, Serial Data (SDA) is disabled internally, and the device does not respond to any requests. After the successful completion of an internal Write cycle (tW), the device internal address counter is automatically incremented to point to the next byte after the last modified byte. If the Write Control input (WC) is driven High, the Write instruction is not executed and the accompanying data bytes are not acknowledged, as shown in Figure 6. DocID027947 Rev 2 15/38 37 Instructions 4.1.1 M24M02-A125 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 (see Figure 6). 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 5. Figure 5. Write mode sequences with WC = 0 (data write enabled) 7# !#+ !#+ "YTE ADDR "YTE ADDR !#+ $ATA IN 3TOP $EV SEL 3TART "YTE 7RITE !#+ 27 7# !#+ "YTE ADDR $EV SEL 3TART 0AGE 7RITE !#+ !#+ "YTE ADDR !#+ $ATA IN $ATA IN 27 7# CONTgD !#+ $ATA IN . 3TOP 0AGE 7RITE CONTgD !#+ 16/38 DocID027947 Rev 2 !)D M24M02-A125 Page Write The Page Write mode allows up to N(1) bytes to be written in a single Write cycle, provided that they are all located in the same page in the memory: that is, the most significant memory address bits, A17/A8, are the same. If more bytes are sent than will fit up to the end of the page, a condition known as “roll-over” occurs. In case of roll-over, the first bytes of the page are overwritten. The bus master sends from 1 to N(1) 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 received by the device is not acknowledged, as shown in Figure 6. After each byte is transferred, the internal byte address counter is incremented. The transfer is terminated by the bus master generating a Stop condition. Figure 6. Write mode sequences with WC = 1 (data write inhibited) 7# !#+ !#+ "YTE ADDR !#+ "YTE ADDR ./ !#+ $ATA IN 3TOP $EV SEL 3TART "YTE 7RITE 27 7# !#+ 0AGE 7RITE $EV SEL 3TART !#+ "YTE ADDR !#+ "YTE ADDR ./ !#+ $ATA IN $ATA IN 27 7# CONTgD ./ !#+ 0AGE 7RITE CONTgD ./ !#+ $ATA IN . 3TOP 4.1.2 Instructions !)D 1. N is the number of bytes in a page. DocID027947 Rev 2 17/38 37 Instructions 4.1.3 M24M02-A125 Write Identification Page The Identification Page (256 byte) is an additional page which can be written and (later) permanently locked in Read-only mode. It is written by issuing the Write Identification Page instruction. This instruction uses the same protocol and format as Page Write (into memory array), except for the following differences: • Device type identifier = 1011b • Most significant address bits A17/A8 are don't care, except for address bit A10 which must be “0”. Least significant address bits A7/A0 define the byte location inside the Identification page. If the Identification page is locked, the data bytes transferred during the Write Identification Page instruction are not acknowledged (NoAck). 4.1.4 Lock Identification Page The Lock Identification Page instruction (Lock ID) permanently locks the Identification page in Read-only mode. The Lock ID instruction is similar to Byte Write (into memory array) with the following specific conditions: 4.1.5 • Device type identifier = 1011b • Address bit A10 must be ‘1’; all other address bits are don't care • The data byte must be equal to the binary value xxxx xx1x, where x is don't care Minimizing Write delays by polling on ACK The maximum Write time (tw) is shown in AC characteristics tables in Section 8: DC and AC parameters, 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 7, is: 18/38 • 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). DocID027947 Rev 2 M24M02-A125 Instructions Figure 7. Write cycle polling flowchart using ACK :ULWHF\FOH LQSURJUHVV 6WDUWFRQGLWLRQ 'HYLFHVHOHFW ZLWK5: 12 )LUVWE\WHRILQVWUXFWLRQ ZLWK5: DOUHDG\ GHFRGHGE\WKHGHYLFH $&. UHWXUQHG <(6 12 1H[W 2SHUDWLRQLV DGGUHVVLQJWKH PHPRU\ <(6 6HQG$GGUHVV DQG5HFHLYH$&. 5H6WDUW 6WRS 12 'DWDIRUWKH :ULWHFSHUDWLRQ &RQWLQXHWKH :ULWHRSHUDWLRQ 6WDUW&RQGLWLRQ <(6 'HYLFHVHOHFW ZLWK5: &RQWLQXHWKH 5DQGRP5HDGRSHUDWLRQ $,H DocID027947 Rev 2 19/38 37 Instructions 4.2 M24M02-A125 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 internal address counter is incremented by one, to point to the next byte address. Figure 8. Read mode sequences !#+ $ATA OUT 3TOP 3TART $EV SEL ./ !#+ 27 !#+ 2ANDOM !DDRESS 2EAD "YTE ADDR $EV SEL !#+ ./ !#+ $ATA OUT . 27 !#+ !#+ "YTE ADDR !#+ "YTE ADDR 27 !#+ $EV SEL 3TART 3TART $EV SEL !#+ $ATA OUT 27 !#+ $ATA OUT ./ !#+ 3TOP 3TART $EV SEL 3EQUENTIAL 2ANDOM 2EAD !#+ "YTE ADDR 27 !#+ 3EQUENTIAL #URRENT 2EAD !#+ 3TART 3TART $EV SEL !#+ 3TOP #URRENT !DDRESS 2EAD !#+ $ATA OUT 27 ./ !#+ 3TOP $ATA OUT . 4.2.1 !)E Random Address Read The Random Address Read is a sequence composed of a truncated Write sequence (to define a new address pointer value, see Table 3) followed by a current Read. The Random Address Read sequence is therefore the sum of [Start + Device Select code with RW=0 + two address bytes] (without Stop condition, as shown in Figure 8)] and [Start condition + Device Select code with RW=1]. The memory device acknowledges the sequence and then outputs the contents of the addressed byte. To terminate the data transfer, the bus master does not acknowledge the last data byte and then issues a Stop condition. 20/38 DocID027947 Rev 2 M24M02-A125 4.2.2 Instructions 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 pointed by the internal address counter. The counter is then incremented. The bus master terminates the transfer with a Stop condition, as shown in Figure 8, without acknowledging the byte. Note that the address counter value is defined by instructions accessing either the memory or the Identification page. When accessing the Identification page, the address counter value is loaded with the Identification page byte location, when accessing the memory, it is safer to always use the Random Address Read instruction (this instruction loads the address counter with the byte location to read in the memory) instead of the Current Address Read instruction. 4.2.3 Sequential Read A sequential Read can be used after a Current Address Read or a Random Address Read. After a Read instruction, the device can continue to output the next byte(s) in sequence if the bus master sends additional clock pulses and if the bus master does acknowledge each transmitted data byte. 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 8. The sequential read is controlled with the device internal address counter which is 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. 4.2.4 Read Identification Page The Identification Page can be read by issuing a Read Identification Page instruction. This instruction uses the same protocol and format as the Random Address Read (from memory array) with device type identifier defined as 1011b. The most significant address bits A17/A8 are don't care and the least significant address bits A7/A0 define the byte location inside the Identification page. The number of bytes to read in the ID page must not exceed the page boundary. 4.2.5 Read the lock status The locked/unlocked status of the Identification page can be checked by transmitting a specific truncated command [Identification Page Write instruction + one data byte] to the device. The device returns an acknowledge bit after the data byte if the Identification page is unlocked, otherwise a NoAck bit if the Identification page is locked. Right after this, it is recommended to transmit to the device a Start condition followed by a Stop condition, so that: • Start: the truncated command is not executed because the Start condition resets the device internal logic, • Stop: the device is then set back into Standby mode by the Stop condition. DocID027947 Rev 2 21/38 37 Instructions 4.2.6 M24M02-A125 Acknowledge in Read mode For all Read instructions, the device waits, after each byte sent out, for an acknowledgment during the 9th bit time. If the bus master does not send the Acknowledge (the master drives SDA high during the 9th bit time), the device terminates the data transfer and enters its Standby mode. 22/38 DocID027947 Rev 2 M24M02-A125 Application design recommendations 5 Application design recommendations 5.1 Supply voltage 5.1.1 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). 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). 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. 5.1.2 Power-up conditions When the power supply is turned on, the VCC voltage has to rise continuously from 0 V up to the minimum VCC operating voltage defined in Table 7. In order to prevent inadvertent write operations during power-up, a power-on-reset (POR) circuit is included. At power-up, the device does not respond to any instruction until VCC reaches the internal threshold voltage (this threshold is defined in the DC characteristic Table 10 as VRES). When VCC passes over the POR threshold, the device is reset and in the following state: • in the Standby power mode • deselected As soon as the VCC voltage has reached a stable value within the [VCC(min), VCC(max)] range (defined in Table 7), the device is ready for operation. 5.1.3 Power-down During power-down (continuous decrease in the VCC supply voltage below the minimum VCC operating voltage defined in Table 7), the device must be in Standby power mode (that is after a STOP condition or after the completion of the Write cycle tW if an internal Write cycle is in progress). DocID027947 Rev 2 23/38 37 Application design recommendations 5.2 M24M02-A125 Cycling with Error Correction Code (ECC) The Error Correction Code (ECC) is an internal logic function which is transparent for the I2C communication protocol. The ECC logic is implemented on each group of four EEPROM bytes(1). Inside a group, if a single bit out of the four bytes happens to be erroneous during a Read operation, the ECC detects this bit and replaces it with the correct value. The read reliability is therefore much improved. Even if the ECC function is performed on groups of four bytes, a single byte can be written/cycled independently. In this case, the ECC function also writes/cycles the three other bytes located in the same group(1). As a consequence, the maximum cycling budget is defined at group level and the cycling can be distributed over the 4 byte of the group: the sum of the cycles seen by byte0, byte1, byte2 and byte3 of the same group must remain below the maximum value defined in Table 6. Example 1: maximum cycling limit reached with 1 million cycles per byte Each byte of a group can be equally cycled 1 million times (at 25 °C) so that the group cycling budget is 4 million cycles. Example 2: maximum cycling limit reached with unequal byte cycling Inside a group, byte0 can be cycled 2 million times, byte1 can be cycled 1 million times, byte2 and byte3 can be cycled 500,000 times, so that the group cycling budget is 4 million cycles at 25 °C. 1. A group of four bytes is located at addresses [4*N, 4*N+1, 4*N+2, 4*N+3], where N is an integer. 24/38 DocID027947 Rev 2 M24M02-A125 6 Delivery state Delivery state The device is delivered as follows: 7 • The memory array is set to all 1s (each byte = FFh). • Identification page: the first three bytes define the Device identification code (value defined in Table 4). The content of the following bytes is Don’t Care. Maximum rating Stressing the device outside the ratings listed in Table 5 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. Table 5. Absolute maximum ratings Symbol TSTG TLEAD Parameter Min. Max. Unit Ambient operating temperature –40 130 °C Storage temperature –65 150 °C (1) °C –0.50 6.5 V - 5 mA –0.50 6.5 V - 3000 V Lead temperature during soldering VIO Input or output range IOL DC output current (SDA = 0) VCC Supply voltage VESD Electrostatic pulse (Human Body model)(2) see note 1. Compliant with JEDEC Standard J-STD-020D (for small body, Sn-Pb or Pb-free assembly), the ST ECOPACK® 7191395 specification, and the European directive on Restrictions of Hazardous Substances (RoHS directive 2011/65/EU of July 2011). 2. Positive and negative pulses applied on pin pairs, according to AEC-Q100-002 (compliant with ANSI/ESDA/JEDEC JS-001-2012, C1=100 pF, R1=1500 Ω, R2=500 Ω). DocID027947 Rev 2 25/38 37 DC and AC parameters 8 M24M02-A125 DC and AC parameters This section summarizes the operating and measurement conditions, and the DC and AC characteristics of the device. Table 6. Cycling performance by groups of 4 byte Symbol Parameter Test condition Min. Max. - 4,000,000 TA ≤ 25 °C, 2.5 V < VCC < 5.5 V Ncycle Write cycle TA = 85 °C, 2.5 V < VCC < 5.5 V endurance(1) TA = 105 °C, 2.5 V < V < 5.5 V CC - 1,200,000 - 300,000 TA = 125 °C, 2.5 V < VCC < 5.5 V - 100,000 Unit Write cycle(2) 1. The Write cycle endurance is defined for groups of four data bytes located at addresses [4*N, 4*N+1, 4*N+2, 4*N+3] where N is an integer, or for the status register byte (refer also to Section 5.2: Cycling with Error Correction Code (ECC)). The Write cycle endurance is defined by characterization and qualification. 2. A Write cycle is executed when either a Page Write, a Byte Write, a Write Identification Page or a Lock Identification Page instruction is decoded. When using those Write instructions, refer also to Section 5.2: Cycling with Error Correction Code (ECC). Table 7. Operating conditions (voltage range W) Symbol VCC TA Parameter Min. Max. Unit Supply voltage 2.5 5.5 V Ambient operating temperature –40 125 °C Max. Unit Table 8. AC measurement conditions Symbol Cbus 26/38 Parameter Min. Load capacitance 100 - SCL input rise/fall time, SDA input fall time - Input levels 0.2 VCC to 0.8 VCC V - Input and output timing reference levels 0.3 VCC to 0.7 VCC V DocID027947 Rev 2 - pF 50 ns M24M02-A125 DC and AC parameters Figure 9. AC measurement I/O waveform )NPUT VOLTAGE LEVELS )NPUT AND OUTPUT 4IMING REFERENCE LEVELS 6## 6## 6## 6## -36 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 VIN < 0.3 VCC 30 - kΩ VIN > 0.7 VCC 500 - kΩ ZL ZH Input impedance (E2, WC)(2) 1. Characterized only, not tested in production. 2. E2 input impedance when the memory is selected (after a Start condition). DocID027947 Rev 2 27/38 37 DC and AC parameters M24M02-A125 Table 10. DC characteristics Symbol Test conditions (in addition to those in Table 7 and Table 8) Parameter Min. Max. Unit ILI Input leakage current (SCL, SDA, E2) VIN = VSS or VCC, device in Standby mode - ±2 µA ILO Output leakage current SDA in Hi-Z, external voltage applied on SDA: VSS or VCC - ±2 µA fC = 400 kHz, VCC = 5.5 V - 2 mA fC = 400 kHz, VCC = 2.5 V - 2 mA fC = 1 MHz, VCC = 5.5 V - 2 mA fC = 1 MHz, VCC = 2.5 V - 2 mA During tW - 2(1) mA Device not t° = 85 °C VIN = VSS or VCC, VCC = 2.5 V - 5 Device not selected(1)(2), t° = 85 °C, VIN = VSS or VCC, VCC = 5.5 V - 5 Device not selected(2), t° = 105 °C, VIN = VSS or VCC, VCC = 2.5 V - 15 Device not selected(2), t° = 105 °C, VIN = VSS or VCC, VCC = 5.5 V - 15 Device not selected(2), t° = 125 °C, VIN = VSS or VCC, VCC = 2.5 V - 20 Device not selected(2), t° = 125 °C, VIN = VSS or VCC, VCC = 5.5 V - 40 ICC ICC0 Supply current (Read) Supply current (Write) selected(1)(2), ICC1 VIL VIH VOL VRES(1) Standby supply current µA Input low voltage (SCL, SDA, WC) - –0.45 0.3 VCC V Input high voltage (SCL, SDA) - 0.7 VCC 6.5 V Input high voltage (WC, E2) - 0.7 VCC VCC +1 V Output low voltage IOL = 2.1 mA, VCC = 2.5 V or IOL = 3 mA, VCC = 5.5 V - 0.4 V Internal reset threshold voltage - 0.5 1.5 V 1. Characterized only, not 100% tested. 2. The device is not selected after power-up, after a Read instruction (after the Stop condition), or after the completion of the internal write cycle tW (tW is triggered by the correct decoding of a Write instruction). 28/38 DocID027947 Rev 2 M24M02-A125 DC and AC parameters Table 11. 400 kHz AC characteristics Parameter(1) Symbol Alt. fC fSCL Clock frequency tCHCL tHIGH tCLCH tQL1QL2(2) tXH1XH2 Min. Max. Unit - 400 kHz Clock pulse width high 600 - ns tLOW Clock pulse width low 1300 - ns tF SDA (out) fall time(3) 20 120 ns Input signal rise time (4) (4) ns (4) (4) ns 100 - ns 0 - ns 100 - ns - 900 ns tR tXL1XL2 tF Input signal fall time tDXCX tSU:DAT Data in set up time tCLDX tHD:DAT Data in hold time tCLQX (5) tDH Data out hold time tCLQV (6) tAA Clock low to next data valid (access time) tCHDL tSU:STA Start condition setup 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 tWLDL(7)(2) tSU:WC WC set up time (before the Start condition) 0 - µs tDHWH(8)(2) tHD:WC WC hold time (after the Stop condition) 1 - µs tW tWR Write time - 5 ms tNS(2) - Pulse width ignored (input filter on SCL and SDA) - single glitch - 80 ns 1. Test conditions (in addition to those in Table 7 and Table 8). 2. Characterized value, not tested in production. 3. With CL = 10 pF. 4. There is no min. or max. values for the input signal rise and fall times. It is however recommended by the I²C specification that the input signal rise and fall times be more than 20 ns and less than 300 ns when fC < 400 kHz. 5. To avoid spurious Start and Stop conditions, a minimum delay is placed between SCL=1 and the falling or rising edge of SDA. 6. tCLQV is the time (from the falling edge of SCL) required by the SDA bus line to reach either 0.3VCC or 0.7VCC, assuming that Rbus × Cbus time constant is within the values specified in Figure 10. 7. WC=0 set up time condition to enable the execution of a WRITE command. 8. WC=0 hold time condition to enable the execution of a WRITE command. DocID027947 Rev 2 29/38 37 DC and AC parameters M24M02-A125 Table 12. 1 MHz AC characteristics Parameter(1) Symbol Alt. Min. Max. Unit fC fSCL Clock frequency 0 1 MHz tCHCL tHIGH Clock pulse width high 260 - ns tCLCH tLOW Clock pulse width low 400 - ns tXH1XH2 tR Input signal rise time (2) (2) ns (2) (2) ns tXL1XL2 tF Input signal fall time tQL1QL2(3) tF SDA (out) fall time - 120 ns tDXCX tSU:DAT Data in setup time 50 - ns tCLDX tHD:DAT Data in hold time 0 - ns 100 - ns - 450 ns 250 - ns tCLQX(4) tDH Data out hold time tCLQV(5) tAA Clock low to next data valid (access time) tCHDL tSU:STA tDLCL tHD:STA Start condition hold time 250 - ns tCHDH tSU:STO Stop condition setup time 250 - ns Start condition setup time tDHDL tBUF Time between Stop condition and next Start condition 500 - ns tWLDL(6) (3) tSU:WC WC set up time (before the Start condition) 0 - µs tDHWH(7) (3) tHD:WC WC hold time (after the Stop condition) 1 - µs tW tWR Write time - 4 ms tNS(3) - Pulse width ignored (input filter on SCL and SDA) - 80 ns 1. Test conditions (in addition to those in Table 7 and Table 8). 2. There is no min. or max. values for the input signal rise and fall times. However, it is recommended by the I²C specification that the input signal rise and fall times be more than 20 ns and less than 120 ns when fC < 1 MHz. 3. Characterized only, not tested in production. 4. To avoid spurious Start and Stop conditions, a minimum delay is placed between SCL=1 and the falling or rising edge of SDA. 5. tCLQV is the time (from the falling edge of SCL) required by the SDA bus line to reach either 0.3 VCC or 0.7 VCC, assuming that the Rbus × Cbus time constant is within the values specified in Figure 11. 6. WC=0 set up time condition to enable the execution of a WRITE command. 7. WC=0 hold time condition to enable the execution of a WRITE command. 30/38 DocID027947 Rev 2 M24M02-A125 DC and AC parameters Figure 10. Maximum Rbus value versus bus parasitic capacitance (Cbus) for an I2C bus at maximum frequency fC = 400 kHz "US LINE PULL UP RESISTOR K K½ 4HE 2 BUS X #BUS TIME CONSTANT MUST BE BELOW THE NS TIME CONSTANT LINE REPRESENTED ON THE LEFT 2 BU S § # BU S (ERE 2BUS § #BUS NS 6## 2BUS N S )£# BUS MASTER 3#, -XXX 3$! P& "US LINE CAPACITOR P& #BUS AIB Figure 11. Maximum Rbus value versus bus parasitic capacitance Cbus) for an I2C bus at maximum frequency fC = 1MHz "US LINE PULL UP RESISTOR K 6## 4HE 2BUS § #BUS TIME CONSTANT MUST BE BELOW THE NS TIME CONSTANT LINE REPRESENTED ON THE LEFT 2 BUS § # BUS NS 2BUS )£# BUS MASTER 3#, -XXX 3$! (ERE 2 BUS § #BUS NS #BUS "US LINE CAPACITOR P& -36 DocID027947 Rev 2 31/38 37 DC and AC parameters M24M02-A125 Figure 12. AC waveforms ^ƚĂƌƚ ĐŽŶĚŝƚŝŽŶ ^ƚĂƌƚ ^ƚŽƉ ĐŽŶĚŝƚŝŽŶ ĐŽŶĚŝƚŝŽŶ ƚy>ϭy>Ϯ ƚy,ϭy,Ϯ ƚ,> ƚ>, ^> ƚ>> ƚy>ϭy>Ϯ ^/Ŷ ƚ,> ƚy,ϭy,Ϯ ^ /ŶƉƵƚ ^ ƚy, ŚĂŶŐĞ ƚ>y ƚ,, ƚ,> t ƚ,t, ƚt>> ^ƚŽƉ ĐŽŶĚŝƚŝŽŶ ^ƚĂƌƚ ĐŽŶĚŝƚŝŽŶ ^> ^/Ŷ ƚt ƚ,, ƚ,> tƌŝƚĞĐLJĐůĞ ƚ,> ^> ƚ>Ys ^KƵƚ ƚ>Yy ĂƚĂǀĂůŝĚ ƚY>ϭY>Ϯ ĂƚĂǀĂůŝĚ /ϬϬϳϵϱŝ 32/38 DocID027947 Rev 2 M24M02-A125 9 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. 9.1 SO8N package information Figure 13. SO8N – 8 lead plastic small outline, 150 mils body width, package outline K[Û $ $ F FFF E H PP *$8*(3/$1( ' N ( ( $ / / 62$B9 1. Drawing is not to scale. DocID027947 Rev 2 33/38 37 Package mechanical data M24M02-A125 Table 13. SO8N – 8 lead plastic small outline, 150 mils body width, package data inches (1) millimeters Symbol Typ Min Max Typ Min Max A - - 1.750 - - 0.0689 A1 - 0.100 0.250 - 0.0039 0.0098 A2 - 1.250 - - 0.0492 - b - 0.280 0.480 - 0.0110 0.0189 c - 0.170 0.230 - 0.0067 0.0091 ccc - - 0.100 - - 0.0039 D 4.900 4.800 5.000 0.1929 0.1890 0.1969 E 6.000 5.800 6.200 0.2362 0.2283 0.2441 E1 3.900 3.800 4.000 0.1535 0.1496 0.1575 e 1.270 - - 0.0500 - - h - 0.250 0.500 - 0.0098 0.0197 k - 0° 8° - 0° 8° L - 0.400 1.270 - 0.0157 0.0500 L1 1.040 - - 0.0409 - - 1. Values in inches are converted from mm and rounded to four decimal digits. 34/38 DocID027947 Rev 2 M24M02-A125 10 Part numbering Part numbering Table 14. Ordering information scheme Example: M24M02 -D W MN 3 T P /K Device type M24 = I2C serial access EEPROM Device function M02-D = 2Mbit (256 K x 8 bits) plus identification page Operating voltage W = VCC = 2.5 V to 5.5 V Package MN = SO8 (150 mil width)(1) Device grade 3 = -40 to 125 °C. Device tested with high reliability certified flow(2) Option blank = tube packing T = Tape and reel packing Plating technology P or G = ECOPACK2® Process /K = Manufacturing technology code 1. The package is ECOPACK2® (RoHS compliant and free of brominated, chlorinated and antimony-oxide flame retardants). 2. The high reliability certified flow (HRCF) is described in quality note QNEE9801. Please ask your nearest ST sales office for a copy. For a list of available options (speed, package, etc.) or for further information on any aspect of the devices, please contact your nearest ST sales office. DocID027947 Rev 2 35/38 37 Part numbering M24M02-A125 Engineering samples Parts marked as “ES”, “E” or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering samples to run qualification activity. 36/38 DocID027947 Rev 2 M24M02-A125 11 Revision history Revision history Table 15. Document revision history Date Revision Changes 07-Jul-2015 1 Initial release. 08-Sep-2015 2 Updated Table 10. Document classification changed from Preliminary Data to Production Data. DocID027947 Rev 2 37/38 37 M24M02-A125 IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. © 2015 STMicroelectronics – All rights reserved 38/38 DocID027947 Rev 2