S524LB0X91/B0XB1 32K/64K-bit Serial EEPROM Data Sheet OVERVIEW The S524LB0D91/B0DB1 serial EEPROM has a 32/64 Kbits (4,096/8,192 bytes) capacity, supporting the standard I2C™-bus serial interface. It is fabricated using Samsung’s most advanced CMOS technology. One of its major features is a hardware-based write protection circuit for the entire memory area. Hardware-based write protection is controlled by the state of the write-protect (WP) pin. Using one-page write mode, you can load up to 32 bytes of data into the EEPROM in a single write operation. Another significant feature of the S524LB0D91/B0DB1 is its support for fast mode and standard mode. FEATURES I2C-Bus Interface Operating Characteristics • Two-wire serial interface • Operating voltage: 2.0 V to 5.5 V • Automatic word address increment • Operating current — Maximum write current: < 3 mA at 5.5 V EEPROM • 32/64 Kbits (4,096/8,192 bytes) storage area • 32-byte page buffer • Typical 3-millisecond write cycle time with autoerase function • Hardware-based write protection for the entire EEPROM (using the WP pin) • EEPROM programming voltage generated on chip • 1,000,000 erase/write cycles • 100 years data retention — Maximum read current: < 500 µA at 5.5 V — Maximum stand-by current: < 2 µA at 2.0 V • Operating temperature range: — – 25 °C to + 70 °C (Commercial) — – 40 °C to + 85 °C (Industrial) • Operating clock frequencies — 100 kHz at standard mode — 400 kHz at fast mode • Electrostatic discharge (ESD) — 5,000 V (HBM) — 500 V (MM) Packages • 8-pin DIP and SOP 7-1 S524LB0D91/B0DB1 SERIAL EEPROM SDA HV Generation Timing Control Start/Stop Logic Control Logic WP SCL DATA SHEET Slave Address Comparator Word Address Pointer Row Decoder EEPROM Cell Array 4,096 x 8 Bits 8,192 x 8 Bits A0 A1 A2 Column Decoder Data Register D OUT and ACK Figure 7-1. S524LB0D91/B0DB1 Block Diagram 7-2 DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM VCC WP SCL SDA S524AB0D91/B0DB1 A0 NOTE: A1 A2 VSS The S524AB0D91/B0DB1 is available in 8-pin DIP, SOP, and TSSOP package. Figure 7-2. Pin Assignment Diagram Table 7-1. S524LB0D91/B0DB1 Pin Descriptions Name Type A0, A1, A2 Input VSS – SDA I/O SCL Description Circuit Number Input pins for device address selection. To configure a device address, these pins should be connected to the VCC or VSS of the device. 1 Ground pin. – 2 Bi-directional data pin for the I C-bus serial data interface. Schmitt trigger input and open-drain output. An external pull-up resistor must be connected to VDD. 3 Input Schmitt trigger input pin for serial clock input. 2 WP Input Input pin for hardware write protection control. If you tie this pin to VCC, the write function is disabled to protect previously written data in the entire memory; if you tie it to VSS, the write function is enabled. 1 VCC – Single power supply. – NOTE: See the following page for diagrams of pin circuit types 1, 2, and 3. 7-3 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET A0, A1, A2, WP Noise Filter SCL Figure 7-3. Pin Circuit Type 1 Figure 7-4. Pin Circuit Type 2 SDA Data Out VSS Noise Filter Figure 7-5. Pin Circuit Type 3 7-4 Data In DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM FUNCTION DESCRIPTION I2C-BUS INTERFACE The S524LB0D91/B0DB1 supports the I2C-bus serial interface data transmission protocol. The two-wire bus consists of a serial data line (SDA) and a serial clock line (SCL). The SDA and the SCL lines must be connected to VCC by a pull-up resistor that is located somewhere on the bus. Any device that puts data onto the bus is defined as a “transmitter” and any device that gets data from the bus is a “receiver.” The bus is controlled by a master device which generates the serial clock and start/stop conditions, controlling bus access. Using the A0, A1, and A2 input pins, up to eight S524LB0D91/B0DB1 devices can be connected to the same I2C-bus as slaves (see Figure 7-6). Both the master and slaves can operate as a transmitter or a receiver, but the master device determines which bus operating mode would be active. VCC VCC R R SDA SCL Slave 1 Bus Master (Transmitter/ Receiver) Slave 2 Slave 3 Slave 8 S524LB0D91/ B0XB1 Tx/Rx A0 A1 A2 S524LB0D91/ B0XB1 Tx/Rx A0 A1 A2 S524LB0D91/ B0XB1 Tx/Rx A0 A1 A2 S524LB0D91/ B0XB1 Tx/Rx A0 A1 A2 To VCC or V SS To VCC or V SS To VCC or V SS To VCC or V SS MCU Figure 7-6. Typical Configuration 7-5 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET I2C-BUS PROTOCOLS Here are several rules for I2C-bus transfers: — A new data transfer can be initiated only when the bus is currently not busy. — MSB is always transferred first in transmitting data. — During a data transfer, the data line (SDA) must remain stable whenever the clock line (SCL) is High. The I2C-bus interface supports the following communication protocols: Bus not busy: The SDA and the SCL lines remain in High level when the bus is not active. • Start condition: A start condition is initiated by a High-to-Low transition of the SDA line while SCL remains in High level. All bus commands must be preceded by a start condition. • Stop condition: A stop condition is initiated by a Low-to-High transition of the SDA line while SCL remains in High level. All bus operations must be completed by a stop condition (see Figure 7-7). ~ ~ • ~ ~ SCL SDA Start Condition Data or ACK Valid Data Change Stop Condition Figure 7-7. Data Transmission Sequence • Data valid: Following a start condition, the data becomes valid if the data line remains stable for the duration of the High period of SCL. New data must be put onto the bus while SCL is Low. Bus timing is one clock pulse per data bit. The number of data bytes to be transferred is determined by the master device. The total number of bytes that can be transferred in one operation is theoretically unlimited. • ACK (Acknowledge): An ACK signal indicates that a data transfer is completed successfully. The transmitter (the master or the slave) releases the bus after transmitting eight bits. During the 9th clock, which the master generates, the receiver pulls the SDA line low to acknowledge that it has successfully received the eight bits of data (see Figure 7-8). But the slave does not send an ACK if an internal write cycle is still in progress. In data read operations, the slave releases the SDA line after transmitting 8 bits of data and then monitors the line for an ACK signal during the 9th clock period. If an ACK is detected but no stop condition, the slave will continue to transmit data. If an ACK is not detected, the slave terminates data transmission and waits for a stop condition to be issued by the master before returning to its stand-by mode. 7-6 DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM Master SCL Line Bit 1 Bit 9 Data from Transmitter ACK from Receiver ACK Figure 7-8. Acknowledge Response From Receiver • Slave Address: After the master initiates a start condition, it must output the address of the device to be accessed. The most significant four bits of the slave address are called the “device identifier.” The identifier for the S524LB0D91/B0DB1 is “1010B”. The next three bits comprise the address of a specific device. The device address is defined by the state of the A0, A1, and A2 pins. Using this addressing scheme, you can cascade up to eight S524LB0D91/B0DB1s on the bus (see Figure 7-9 below). • Read/Write: The final (eighth) bit of the slave address defines the type of operation to be performed. If the R/W bit is “1”, a read operation is executed. If it is “0”, a write operation is executed. Device Identifier Slave Address 1 0 1 Device Select 0 A2 A1 A0 R/W A9 A8 A1 A0 First (High) Address First Word Address X X X(2) A12(1) A11 A10 Second (Low) Address Second Word Address A7 A6 A5 A4 A3 A2 NOTES: 1. The A12 is "don't care" for the S524LB0X91. 2. X = Don't care. Figure 7-9. Device Address 7-7 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET BYTE WRITE OPERATION A write operation requires 2-byte word addresses, the first (high) word address and the second (low) word address. In a byte write operation, the master transmits the slave address, the first word address, the second word address, and one data byte to the S524LB0D91/B0DB1 slave device (see Figure 7-10). Start Slave Address First Word Address A C K Second Word Address A C K Data A C K Stop A C K Figure 7-10. Byte Write Operation Following a start condition, the master puts the device identifier (4 bits), the device address (3 bits), and an R/W bit set to “0” onto the bus. Upon the receipt of the slave address, the S524LB0D91/B0DB1 responds with an ACK. And the master transmits the first word address, the second word address, and one byte data to be written into the addressed memory location. The master terminates the transfer by generating a stop condition, at which time the S524LB0D91/B0DB1 begins the internal write cycle. While the internal write cycle is in progress, all S524LB0D91/B0DB1 inputs are disabled and the S524LB0D91/B0DB1 does not respond to any additional request from the master. 7-8 DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM PAGE WRITE OPERATION The S524LB0D91/B0DB1 can also perform 32-byte page write operation. A page write operation is initiated in the same way as a byte write operation. However, instead of finishing the write operation after the first data byte is transferred, the master can transmit up to 31 additional bytes. The S524LB0D91/B0DB1 responds with an ACK each time it receives a complete byte of data (see Figure 7-11). Start Slave Address First Word Address Second Word Address Data Byte N (N <= 31) Data Byte 0 Stop ... A C K A C K A C K A C K A C K A C K Figure 7-11. Page Write Operation The S524LB0D91/B0DB1 automatically increments the word address pointer each time it receives a complete data byte. When one byte is received, the internal word address pointer increments to the next address so that the next data byte can be received. If the master transmits more than 32 bytes before it generates a stop condition to end the page write operation, the S524LB0D91/B0DB1 word address pointer value “rolls over” and the previously received data is overwritten. If the master transmits less than 32 bytes and generates a stop condition, the S524LB0D91/B0DB1 writes the received data to the corresponding EEPROM address. During a page write operation, all inputs are disabled and there would be no response to additional requests from the master until the internal write cycle is completed. 7-9 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET POLLING FOR AN ACK SIGNAL When the master issues a stop condition to initiate a write cycle, the S524LB0D91/B0DB1 starts an internal write cycle. The master can then immediately begin polling for an ACK from the slave device to determine whether the write cycle is completed. To poll for an ACK signal in a write operation, the master issues a start condition followed by the slave address. As long as the S524LB0D91/B0DB1 remains busy with the write operation, no ACK is returned. When the S524LB0D91/B0DB1 completes the write operation, it returns an ACK and the master can then proceed with the next read or write operation (see Figure 7-12). Send write command Send Stop condition to initiate write cycle Send Start condition Send slave address with R/ W bit = “0” ACK = “0” ? No Yes Start next operation Figure 7-12. Master Polling for an ACK Signal from a Slave Device 7-10 DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM HARDWARE-BASED WRITE PROTECTION You can also write-protect the entire memory area of the S524LB0D91/B0DB1. This write protection is controlled by the state of the Write Protect (WP) pin. When the WP pin is connected to VCC, any attempt to write a value to it is ignored. The S524LB0D91/B0DB1 will acknowledge slave and word addresses, but it will not generate an acknowledge after receiving the first byte of data. In this situation, the write cycle will not be started when a stop condition is generated. By connecting the WP pin to VSS, the write function is allowed for the entire memory. These write protection features effectively change the EEPROM to a ROM in order to protect data from being overwritten. Whenever the write function is disabled, a slave address and word addresses are acknowledged on the bus, but data bytes are not acknowledged. CURRENT ADDRESS BYTE READ OPERATION The internal word address pointer maintains the address of the last word accessed, incremented by one. Therefore, if the last access (either read or write) was to the address “n”, the next read operation would be to access data at address “n+1”. When the S524LB0D91/B0DB1 receives a slave address with the R/W bit set to “1”, it issues an ACK and sends the eight bits of data. In a current address byte read operation, the master does not acknowledge the data, and it generates a stop condition, forcing the S524LB0D91/B0DB1 to stop the transmission (see Figure 7-13). Start Slave Address Data A C K Stop N O A C K Figure 7-13. Current Address Byte Read Operation 7-11 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET RANDOM ADDRESS BYTE READ OPERATION Using random read operations, the master can access any memory location at any time. Before it issues the slave address with the R/W bit set to “1”, the master must first perform a “dummy” write operation. This operation is performed in the following steps: 1. The master first issues a start condition, the slave address, and the word address (the first and the second addresses) to be read. (This step sets the internal word address pointer of the S524LB0D91/B0DB1 to the desired address.) 2. When the master receives an ACK for the word address, it immediately re-issues a start condition followed by another slave address, with the R/W bit set to “1”. 3. The S524LB0D91/B0DB1 then sends an ACK and the 8-bit data stored at the pointed address. 4. At this point, the master does not acknowledge the transmission, generating a stop condition. 5. The S524LB0D91/B0DB1 stops transmitting data and reverts to stand-by mode (see Figure 7-14). Start Slave Address First Word Address A C K Second Word Address A C K Start A C K Slave Address Data A C K Figure 7-14. Random Address Byte Read Operation 7-12 Stop N O A C K DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM SEQUENTIAL READ OPERATION Sequential read operations can be performed in two ways: current address sequential read operation, and random address sequential read operation. The first data is sent in either of the two ways, current address byte read operation or random address byte read operation described earlier. If the master responds with an ACK, the S524LB0D91/B0DB1 continues transmitting data. If the master does not issue an ACK, generating a stop condition, the slave stops transmission, ending the sequential read operation. Using this method, data is output sequentially from address “n” followed by address “n+1”. The word address pointer for read operations increments to all word addresses, allowing the entire EEPROM to be read sequentially in a single operation. After the entire EEPROM is read, the word address pointer “rolls over” and the S524LB0D91/B0DB1 continues to transmit data for each ACK it receives from the master (see Figure 7-15). Start Slave Address Data (n) Data (n+X) Stop ~ ~ A C K A C K A C K N O A C K Figure 7-15. Sequential Read Operation 7-13 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET ELECTRICAL DATA Table 7-2. Absolute Maximum Ratings (TA = 25 °C) Symbol Conditions Rating Unit Supply voltage VCC – – 0.3 to + 7.0 V Input voltage VIN – – 0.3 to + 7.0 V Output voltage VO – – 0.3 to + 7.0 V Operating temperature TA – – 40 to + 85 °C Storage temperature TSTG – – 65 to + 150 °C Electrostatic discharge VESD HBM 5000 V MM 500 Parameter Table 7-3. D.C. Electrical Characteristics (TA = – 25 °C to + 70 °C (Commercial), – 40 °C to + 85 °C (Industrial), VCC = 2.0 V to 5.5 V) Parameter Symbol Conditions Min Typ Max Unit – – 0.3 VCC V 0.7 VCC – – V Input low voltage VIL Input high voltage VIH Input leakage current ILI VIN = 0 to VCC – – 10 µA Output leakage current ILO VO = 0 to VCC – – 10 µA Output Low voltage VOL IOL = 3 mA, VCC = 2.0 V – – 0.4 V ICC1 VCC = 5.5 V, 400 kHz – – 3 mA ICC2 VCC = 2.0 V, 100 kHz – – 1 ICC3 VCC = 5.5 V, 400 kHz – – 0.5 ICC4 VCC = 2.0 V, 100 kHz – – 0.2 ICC5 VCC = SDA = SCL = 5.5 V, all other inputs = 0 V – – 5 ICC6 VCC = SDA = SCL = 2.0 V, all other inputs = 0 V – – 2 Supply current Write Read Stand-by current 7-14 SCL, SDA, A0, A1, A2 µA DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM Table 7-3. D.C. Electrical Characteristics (Continued) (TA = – 25 °C to + 70 °C (Commercial), – 40 °C to + 85 °C (Industrial), VCC = 2.0 V to 5.5 V) Parameter Symbol Conditions Min Typ Max Unit Input capacitance CIN 25 °C, 1MHz, VCC = 5 V, VIN = 0 V, A0, A1, A2, SCL and WP pin – – 10 pF Input/Output capacitance CI/O 25 °C, 1MHz, VCC = 5 V, VI/O = 0 V, SDA pin – – 10 Table 7-4. A.C. Electrical Characteristics (TA = – 25 °C to + 70 °C (Commercial), – 40 °C to + 85 °C (Industrial), VCC = 2.0 V to 5.5 V) Parameter Symbol Conditions VCC = 2.0 to 5.5 V (Standard Mode) Min Max (1) VCC = 4.5 to 5.5 V (Fast Mode) Unit Min Max 0 400 (1) kHz Fclk – 0 100 Clock High time tHIGH – 4 – 0.6 – µs Clock Low time tLOW – 4.7 – 1.3 – µs External clock frequency Rising time tR SDA, SCL – 1 – 0.3 µs Falling time tF SDA, SCL – 0.3 – 0.3 µs Start condition hold time tHD:STA – 4 – 0.6 – µs Start condition setup time tSU:STA – 4.7 – 0.6 – µs Data input hold time tHD:DAT – 0 – 0 – µs Data input setup time tSU:DAT – 0.25 – 0.1 – µs Stop condition setup time tSU:STO – 4 – 0.6 – µs Bus free time tBUF Before new transmission 4.7 – 1.3 – µs Data output valid from clock low (2) tAA – 0.3 3.5 – 0.9 µs Noise spike width tSP – – 100 – 50 ns Write cycle time tWR – – 5 – 5 ms NOTES: 1. 2. Upon customers request, up to 400 kHz (Max.) in standard mode and 1 MHz in fast mode are available. When acting as a transmitter, the S524LB0D91/B0DB1 must provide an internal minimum delay time to bridge the undefined period (minimum 300 ns) of the falling edge of SCL. This is required to avoid unintended generation of a start or stop condition. 7-15 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET tF tHIGH tR tLOW SCL tSU:STA tHD:STA tHD:DAT tSU:DAT tSU:STO SDA In tAA tBUF SDA Out Figure 7-16. Timing Diagram for Bus Operations ~ ~ SCL 8th Bit ~ ~ ~ ~ SDA ACK WORDn tWR Stop Condition Figure 7-17. Write Cycle Timing Diagram 7-16 Start Condition DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM CHARACTERISTIC CURVES NOTE The characteristic values shown in the following graphs are based on actual test measurements. They do not, however, represent guaranteed operating values. (Frequency = 100 kHz) 2.0 1.6 Temp = -40 C Temp = -25 C 1.2 I CC (mA) Temp = 25 C 0.8 Temp = 70 C Temp = 85 C 0.4 0 1.5 2.5 3.5 4.5 5.5 VCC (V) Figure 7-18. Write Current 7-17 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET (Frequency = 100 kHz) 500 400 Temp = -40 C Temp = -25 C 300 I CC (uA) Temp = 25 C 200 Temp = 70 C Temp = 85 C 100 0 1.5 2.5 3.5 4.5 5.5 VCC (V) Figure 7-19. Read Current (Frequency = 100 kHz) 1.5 1.2 0.9 I CC (uA) Temp = -40 C 0.6 Temp = -25 C Temp = 25 C 0.3 Temp = 70 C Temp = 85 C 0 1.5 2.5 3.5 4.5 VCC (V) Figure 7-20. Stand-by Current 7-18 5.5 DATA SHEET S524LB0D91/B0DB1 SERIAL EEPROM (TA = 25 C) 50 VDD = 6 V 40 VDD = 5 V 30 VDD = 4 V I OL (mA) 20 VDD = 3 V 10 VDD = 2 V 0 0 1 2 3 4 5 6 VOL (V) Figure 7-21. Output Low Voltage 7-19 S524LB0D91/B0DB1 SERIAL EEPROM DATA SHEET NOTES 7-20