Features • • • • • • • • • • • Serial Peripheral Interface (SPI) Compatible Supports SPI Modes 0 (0,0) and 3 (1,1) Low Voltage and Standard Voltage Operation 5.0 (VCC = 4.5V to 5.5V) 2.7 (VCC = 2.7V to 5.5V) 1.8 (VCC = 1.8V to 3.6V) 2.1 MHz Clock Rate 32-Byte Page Mode Block Write Protection Protect 1/4, 1/2, or Entire Array Write Protect (WP) Pin and Write Disable Instructions for Both Hardware and Software Data Protection Self-Timed Write Cycle (5 ms Typical) High Reliability Endurance: 100,000 Cycles Data Retention: 100 Years Automotive Grade and Extended Temperature Devices Available 8-Pin PDIP, 14-pin, 16-pin JEDEC SOIC, and 20-Pin TSSOP Packages SPI Serial E2PROMs 128K (16384 x 8) AT25128 Preliminary Description The AT25128 provides 131,072 bits of serial electrically erasable programmable read only memory (EEPROM) organized as 16,384 words of 8 bits each. The device is optimized for use in many industrial and commercial applications where low power and low voltage operation are essential. The AT25128 is available in space saving 8-pin PDIP, JEDEC SOIC, and 14-pin and 20-pin TSSOP packages. (continued) Pin Configurations Pin Name Function CS Chip Select SCK Serial Data Clock SI Serial Data Input SO Serial Data Output 8-Pin PDIP CS SO WP GND GND Ground VCC Power Supply WP Write Protect HOLD Suspends Serial Input NC No Connect DC Don’t Connect 1 2 3 4 8 7 6 5 14-Pin SOIC 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC HOLD NC NC NC NC SCK SI 14 13 12 11 10 9 8 1 2 3 4 5 6 7 20-Lead TSSOP* 16-Lead SOIC CS SO NC NC NC NC WP GND CS SO NC NC NC WP GND VCC HOLD SCK SI NC CS SO SO NC NC WP GND DC NC 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 NC VCC HOLD HOLD NC NC SCK SI DC NC * Note: Pins 3, 4 and 17, 18 are internally connected for 14-lead TSSOP socket compatibility. VCC HOLD NC NC NC SCK SI Description (Continued) The AT25128 is enabled through the Chip Select pin (CS) and accessed via a 3-wire interface consisting of Serial Data Input (SI), Serial Data Output (SO), and Serial Clock (SCK). All programming cycles are completely self-timed, and no separate ERASE cycle is required before WRITE. tions are provided for additional data protection. Hardware data protection is provided via the WP pin to protect against inadvertent write attempts to the status register. The HOLD pin may be used to suspend any serial communication without resetting the serial sequence. BLOCK WRITE protection is enabled by programming the status register with one of four blocks of write protection. Separate program enable and program disable instruc- Absolute Maximum Ratings* Operating Temperature................... -55°C to +125°C Storage Temperature...................... -65°C to +150°C Voltage on Any Pin with Respect to Ground ..................... -1.0V to +7.0V Maximum Operating Voltage ........................... 6.25V DC Output Current ......................................... 5.0 mA Block Diagram 2 AT25128 *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. AT25128 Pin Capacitance (1) Applicable over recommended operating range from TA = 25°C, f = 1.0 MHz, VCC = +5.0V (unless otherwise noted). Test Conditions Max Units Conditions COUT Output Capacitance (SO) 8 pF VOUT = 0V CIN Input Capacitance (CS, SCK, SI, WP, HOLD) 6 pF VIN = 0V Note: 1. This parameter is characterized and is not 100% tested. DC Characteristics Applicable over recommended operating range from: TAI = -40°C to +85°C, VCC = +1.8V to +5.5V, TAC = 0°C to +70°C, VCC = +1.8V to +5.5V (unless otherwise noted). Symbol Parameter Test Condition Min Typ Max Units VCC1 Supply Voltage 1.8 3.6 V VCC2 Supply Voltage 2.7 5.5 V VCC3 Supply Voltage 4.5 5.5 V ICC1 Supply Current VCC = 5.0V at 1 MHz, SO = Open 3.0 mA ICC2 Supply Current VCC = 5.0V at 2 MHz, SO = Open 5.0 mA ISB1 Standby Current VCC = 1.8V CS = VCC 0.1 µA ISB2 Standby Current VCC = 2.7V CS = VCC 0.2 0.5 µA ISB3 Standby Current VCC = 5.0V CS = VCC 0.5 2.0 µA IIL Input Leakage VIN = 0V to VCC -3.0 3.0 µA IOL Output Leakage VIN = 0V to VCC, TAC = 0°C to 70°C -3.0 3.0 µA VIL (1) Input Low Voltage -1.0 VCC x 0.3 V (1) Input High Voltage VCC x 0.7 VCC + 0.5 V 0.4 V VIH VOL1 Output Low Voltage VOH1 Output High Voltage VOL2 Output Low Voltage VOH2 Output High Voltage Note: 4.5V ≤ VCC ≤ 5.5V IOL = 3.0 mA 1.8V ≤ VCC ≤ 3.6V IOL = 0.15 mA IOH = -1.6 mA VCC - 0.8 IOH = -100 µA VCC - 0.2 V 0.2 V V 1. VIL min and VIH max are reference only and are not tested. 3 AC Characteristics Applicable over recommended operating range from TA = -40°C to +85°C, VCC = As Specified, CL = 1 TTL Gate and 100 pF (unless otherwise noted). Symbol Parameter Voltage Min Max Units fSCK SCK Clock Frequency 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 0 0 0 2.1 2.1 0.5 MHz tRI Input Rise Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 2 2 2 µs tFI Input Fall Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 2 2 2 µs tWH SCK High Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 200 300 800 ns tWL SCK Low Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 200 200 800 ns tCS CS High Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 250 250 1000 ns tCSS CS Setup Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 250 250 1000 ns tCSH CS Hold Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 250 250 1000 ns tSU Data In Setup Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 50 50 100 ns tH Data In Hold Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 50 50 100 ns tHD Hold Setup Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 100 100 400 ns tCD Hold Hold Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 100 100 400 ns tV Output Valid 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 0 0 0 tHO Output Hold Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 0 0 0 tLZ Hold to Output Low Z 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 0 0 0 200 200 800 ns ns 100 100 100 ns (continued) 4 AT25128 AT25128 AC Characteristics (Continued) Symbol Parameter Voltage tHZ Hold to Output High Z tDIS tWC Min Max Units 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 100 100 100 ns Output Disable Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 250 250 1000 ns Write Cycle Time 4.5 - 5.5 2.7 - 5.5 1.8 - 3.6 5 10 20 ms 5 Serial Interface Description MASTER: The device that generates the serial clock. SLAVE: Because the Serial Clock pin (SCK) is always an input, the AT25128 always operates as a slave. TRANSMITTER/RECEIVER: T h e A T 2 5 1 2 8 h a s separate pins designated for data transmission (SO) and reception (SI). MSB: The Most Significant Bit (MSB) is the first bit transmitted and received. SERIAL OP-CODE: After the device is selected with CS going low, the first byte will be received. This byte contains the op-code that defines the operations to be performed. INVALID OP-CODE: If an invalid op-code is received, no data will be shifted into the AT25128, and the serial output pin (SO) will remain in a high impedance state until the falling edge of CS is detected again. This will reinitialize the serial communication. CHIP SELECT: The AT25128 is selected when the CS pin is low. When the device is not selected, data will not be accepted via the SI pin, and the serial output pin (SO) will remain in a high impedance state. HOLD: The HOLD pin is used in conjunction with the CS pin to select the AT25128. When the device is selected and a serial sequence is underway, HOLD can be used to pause the serial communication with the master device without resetting the serial sequence. To pause, the HOLD pin must be brought low while the SCK pin is low. To resume serial communication, the HOLD pin is brought high while the SCK pin is low (SCK may still toggle during HOLD). Inputs to the SI pin will be ignored while the SO pin is in the high impedance state. WRITE PROTECT: The write protect pin (WP) will allow normal read/write operations when held high. When the WP pin is brought low and WPEN bit is “1", all write operations to the status register are inhibited. WP going low while CS is still low will interrupt a write to the status register. If the internal write cycle has already been initiated, WP going low will have no effect on any write operation to the status register. The WP pin function is blocked when the WPEN bit in the status register is ”0". This will allow the user to install the AT25128 in a system with the WP pin tied to ground and still be able to write to the status register. All WP pin functions are enabled when the WPEN bit is set to “1". 6 AT25128 SPI Serial Interface AT25128 Functional Description Table 2b. Read Status Register Bit Definition The AT25128 is designed to interface directly with the synchronous serial peripheral interface (SPI) of the 6805 and 68HC11 series of microcontrollers. The AT25128 utilizes an 8 bit instruction register. The list of instructions and their operation codes are contained in Table 1. All instructions, addresses, and data are transferred with the MSB first. Table 1. Instruction Set for the AT25128 Instruction Instruction Name Format Operation WREN WRDI RDSR WRSR READ WRITE 0000 X110 0000 X100 0000 X101 0000 X001 0000 X011 0000 X010 Set Write Enable Latch Reset Write Enable Latch Read Status Register Write Status Register Read Data from Memory Array Write Data to Memory Array WRITE ENABLE (WREN): The device will power up in the write disable state when VCC is applied. All programming instructions must therefore be preceded by a Write Enable instruction. WRITE DISABLE (WRDI): To protect the device against inadvertent writes, the Write Disable instruction disables all programming modes. The WRDI instruction is independent of the status of the WP pin. READ STATUS REGISTER (RDSR): The Read Status Register instruction provides access to the status register. The READY/BUSY and Write Enable status of the device can be determined by the RDSR instruction. Similarly, the Block Write Protection bits indicate the extent of protection employed. These bits are set by using the WRSR instruction. Table 2a. Status Register Format Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 WPEN X X X BP1 BP0 WEN RDY Bit Definition Bit 0 = 0 (RDY) indicates the device is READY. Bit 0 = 1 indicates the write cycle is in progress. Bit 1= 0 indicates the device is not WRITE Bit 1 (WEN) ENABLED. Bit 1 = 1 indicates the device is WRITE ENABLED. Bit 2 (BP0) See Table 3. Bit 3 (BP1) See Table 3. Bits 4-6 are 0s when device is not in an internal write cycle. Bit 7 (WPEN) See Table 4. Bits 0-7 are 1s during an internal write cycle. Bit 0 (RDY) WRITE STATUS REGISTER (WRSR): The WRSR instruction allows the user to select one of four levels of protection. The AT25128 is divided into four array segments. One quarter (1/4), one half (1/2), or all of the memory segments can be protected. Any of the data within any selected segment will therefore be READ only. The block write protection levels and corresponding status register control bits are shown in Table 3. The three bits, BP0, BP1, and WPEN are nonvolatile cells that have the same properties and functions as the regular memory cells (e.g. WREN, tWC, RDSR). Table 3. Block Write Protect Bits Level 0 Status Register Bits Array Addresses Protected BP1 BP0 AT25128 0 0 None 1(1/4) 0 1 3000 - 3FFF 2(1/2) 1 0 2000 - 3FFF 3(All) 1 1 0000 - 3FFF The WRSR instruction also allows the user to enable or disable the write protect (WP) pin through the use of the Write Protect Enable (WPEN) bit. Hardware write protection is enabled when the WP pin is low and the WPEN bit is “1.” Hardware write protection is disabled when either the WP pin is high or the WPEN bit is “0.” When the device is hardware write protected, writes to the Status Register, including the Block Protect bits and the WPEN bit, and the block-protected sections in the memory array are disabled. Writes are only allowed to sections of the memory which are not block-protected. NOTE: When the WPEN bit is hardware write protected, it cannot be changed back to “0,” as long as the WP pin is held low. (continued) 7 Functional Description (Continued) Table 4. WPEN Operation WPEN WP 0 WEN Protected Unprotected Status Blocks Blocks Register X 0 Protected Protected Protected 0 X 1 Protected Writable Writable 1 Low 0 Protected Protected Protected 1 Low 1 Protected Writable Protected X High 0 Protected Protected Protected X High 1 Protected Writable Writable READ SEQUENCE (READ): Reading the AT25128 via the SO (Serial Output) pin requires the following sequence. After the CS line is pulled low to select a device, the READ op-code is transmitted via the SI line followed by the byte address to be read (A15-A0, Refer to Table 5). Upon completion, any data on the SI line will be ignored. The data (D7-D0) at the specified address is then shifted out onto the SO line. If only one byte is to be read, the CS line should be driven high after the data comes out. The READ sequence can be continued since the byte address is automatically incremented and data will continue to be shifted out. When the highest address is reached, the address counter will roll over to the lowest address allowing the entire memory to be read in one continuous READ cycle. WRITE SEQUENCE (WRITE): In order to program the AT25128, two separate instructions must be executed. First, the device must be write enabled via the Write Enable (WREN) Instruction. Then a Write (WRITE) Instruction may be executed. Also, the address of the memory location(s) to be programmed must be outside the protected address field location selected by the Block Write Protection Level. During an internal write cycle, all commands will be ignored except the RDSR instruction. A Write Instruction requires the following sequence. After the CS line is pulled low to select the device, the WRITE op-code is transmitted via the SI line followed by the byte address (A15-A0) and the data (D7-D0) to be programmed (Refer to Table 5). Programming will start after the CS pin is brought high. (The LOW to High transition of the CS pin must occur during the SCK low time immediately after clocking in the D0 (LSB) data bit. 8 AT25128 The READY/BUSY status of the device can be determined by initiating a READ STATUS REGISTER (RDSR) Instruction. If Bit 0 = 1, the WRITE cycle is still in progress. If Bit 0 = 0, the WRITE cycle has ended. Only the READ STATUS REGISTER instruction is enabled during the WRITE programming cycle. The AT25128 is capable of a 32-byte PAGE WRITE operation. After each byte of data is received, the five low order address bits are internally incremented by one; the high order bits of the address will remain constant. If more than 32-bytes of data are transmitted, the address counter will roll over and the previously written data will be overwritten. The AT25128 is automatically returned to the write disable state at the completion of a WRITE cycle. NOTE: If the device is not Write enabled (WREN), the device will ignore the Write instruction and will return to the standby state, when CS is brought high. A new CS falling edge is required to re-initiate the serial communication. Table 5. Address Key Address AT25128 AN A13 - A0 Don’t Care Bits A15 - A14 AT25128 Timing Diagrams (for SPI Mode 0 (0,0)) Synchronous Data Timing t CS VIH CS VIL t CSH t CSS VIH t WH SCK t WL VIL tH t SU VIH SI VALID IN VIL tV VOH SO HI-Z t HO t DIS HI-Z VOL WREN Timing WRDI Timing 9 RDSR Timing CS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SCK INSTRUCTION SI SO HIGH IMPEDANCE DATA OUT 7 MSB WRSR Timing READ Timing 10 AT25128 6 5 4 3 2 1 0 AT25128 WRITE Timing HOLD Timing CS tCD tCD SCK tHD tHD HOLD tHZ SO tLZ 11 Ordering Information tWC (max) ICC (max) ISB (max) fMAX (ms) (µA) (µA) (kHz) 5 5000 2.0 2100 AT25128-10PC AT25128-10SC AT25128N1-10SC AT25640T2-10TC 8P3 14S 16S1 20T Commercial (0°C to 70°C) 10 3000 0.5 2100 AT25128-10PC-2.7 AT25128-10SC-2.7 AT25128N1-10SC-2.7 AT25128T2-10TC-2.7 8P3 14S 16S1 20T Commercial (0°C to 70°C) 20 3000 0.2 500 AT25128-10PC-1.8 AT25128-10SC-1.8 AT25128N1-10SC-1.8 AT25128T2-10TC-1.8 8P3 14S 16S1 20T Commercial (0°C to 70°C) 5 5000 2.0 2100 AT25128-10PI AT25128-10SI AT25128N1-10SI AT25128T2-10TI 8P3 14S 16S1 20T Industrial (-40°C to 85°C) 10 3000 0.5 2100 AT25128-10PI-2.7 AT25128-10SI-2.7 AT25128N1-10SI-2.7 AT25128T2-10TI-2.7 8P3 14S 16S1 20T Industrial (-40°C to 85°C) 20 3000 0.2 500 AT25128-10PI-1.8 AT25128-10SI-1.8 AT25128N1-10SI-1.8 AT25128T2-10TI-1.8 8P3 14S 16S1 20T Industrial (-40°C to 85°C) Ordering Code Package Package Type 8P3 8-Lead, 0.300" Wide, Plastic Dual Inline Package (PDIP) 14S 14-Lead, 0.150" Wide, Plastic Gull Wing Small Outline Package (JEDEC SOIC) 16S1 16-Lead, 0.150" Wide, Plastic Gull Wing Small Outline Package (JEDEC SOIC) 20T 20-Lead, 0.170" Wide, Thin Super Small Outline Package (TSSOP) Options 12 Blank Standard Device (4.5V to 5.5V) -2.7 Low Voltage (2.7V to 5.5V) -1.8 Low Voltage (1.8V to 3.6V) AT25128 Operation Range