CAT1161/2 (16K) Supervisory Circuits with I2C Serial CMOS EEPROM, Precision Reset Controller and Watchdog Timer FEATURES ■ Active high or low reset ■ Watchdog monitors SDA signal (CAT1161) 2 — Precision power supply voltage monitor ■ 400 kHz I C bus compatible — 5V, 3.3V and 3V systems ■ 2.7 to 6.0 Volt operation — Five threshold voltage options ■ Low power CMOS technology ■ 1,000,000 Program/Erase cycles ■ 16-Byte page write buffer ■ Manual Reset ■ Built-in inadvertent write protection ■ 100 Year data retention — VCC lock out ■ 8-pin DIP or 8-pin SOIC — Write protect pin, WP ■ Commercial and industrial temperature ranges DESCRIPTION The CAT1161/2 is a complete memory and supervisory solution for microcontroller-based systems. A serial EEPROM memory (16K) with hardware memory write protection, a system power supervisor with brown out protection and a watchdog timer are integrated together in low power CMOS technology. Memory interface is via an I2C bus. The 1.6-second watchdog circuit returns a system to a known good state if a software or hardware glitch halts or “hangs” the system. The CAT1161 watchdog monitors the SDA line, making an additional PC board trace unnecessary. The lower cost CAT1162 does not have a watchdog timer. voltages support 5V, 3.3V and 3V systems. If power supply voltages are out of tolerance reset signals become active, preventing the system microcontroller, ASIC or peripherals from operating. Reset signals become inactive typically 200 ms after the supply voltage exceeds the reset threshold level. With both active high and low reset signals, interface to microcontrollers and other ICs is simple. In addition, a reset pin can be used as a debounced input for push-button manual reset capability. The CAT1161/2 memory features a 16-byte page. In addition, hardware data protection is provided by a write protect pin WP and by a VCC sense circuit that prevents writes to memory whenever VCC falls below the reset threshold or until VCC reaches the reset threshold during power up. The power supply monitor and reset circuit protects Available packages include an 8-pin DIP and a surface memory and system controllers during power up/down mount, 8-pin SO package. and against brownout conditions. Five reset threshold BLOCK DIAGRAM PIN CONFIGURATION EXTERNAL LOAD DC RESET WP GND VCC RESET SCL SDA CAT1161/2 SENSE AMPS SHIFT REGISTERS DOUT ACK VCC GND SDA WORD ADDRESS BUFFERS START/STOP LOGIC XDEC DC = Do not connect Part Dash Minimum Number Threshold WP 4.50 4.75 -42 4.25 4.50 -30 3.00 3.15 DATA IN STORAGE HIGH VOLTAGE/ TIMING CONTROL RESET Controller -28 2.85 3.00 -25 2.55 2.70 16K EEPROM CONTROL LOGIC Maximum Threshold -45 COLUMN DECODERS Only for CAT1161 WATCHDOG Precision Vcc Monitor STATE COUNTERS SCL SLAVE ADDRESS COMPARATORS RESET RESET © 2001 by Catalyst Semiconductor, Inc. Characteristics subject to change without notice Doc No. 3002, Rev. C CAT1161/2 PIN FUNCTIONS ABSOLUTE MAXIMUM RATINGS Pin No. Pin Name Temperature Under Bias ................. –55°C to +125°C Function 1 DC 2 RESET 3 WP VCC with Respect to Ground ............... –2.0V to +7.0V 4 GND Ground Package Power Dissipation Capability (TA = 25°C) ................................... 1.0W 5 SDA Serial Data/Address 6 SCL Clock Input Lead Soldering Temperature (10 secs) ............ 300°C 7 RESET 8 VCC Power Supply Min Max Storage Temperature ....................... –65°C to +150°C Voltage on any Pin with Respect to Ground(1) ............ –2.0V to +VCC +2.0V Output Short Circuit Current(2) ........................ 100 mA Do Not Connect Active Low Reset I/O Write Protect Active High Reset I/O Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. RELIABILITY CHARACTERISTICS Symbol NEND (3) Parameter Reference Test Method Units Endurance MIL-STD-883, Test Method 1033 1,000,000 Cycles/Byte TDR(3) Data Retention MIL-STD-883, Test Method 1008 100 Years VZAP(3) ESD Susceptibility MIL-STD-883, Test Method 3015 2000 Volts ILTH(3)(4) Latch-Up JEDEC Standard 17 100 mA D.C. OPERATING CHARACTERISTICS VCC = +2.7V to +6.0V, unless otherwise specified. Symbol Parameter ICC Power Supply Current ISB Standby Current ILI Test Conditions Min Typ Max Units fSCL = 100 KHz 3 mA VCC = 3.3V VCC = 5 40 50 µA µA Input Leakage Current VIN = GND or VCC 2 µA ILO Output Leakage Current VIN = GND or VCC 10 µA VIL Input Low Voltage -1 VCC x 0.3 V VIH Input High Voltage VCC X 0.7 VCC + 0.5 V VOL1 Output Low Voltage (SDA) IOL = 3 mA, VCC = 3.0V 0.4 V Note: (1) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns. Maximum DC voltage on output pins is VCC +0.5V, which may overshoot to VCC +2.0V for periods of less than 20 ns. (2) Output shorted for no more than one second. No more than one output shorted at a time. (3) This parameter is tested initially and after a design or process change that affects the parameter. (4) Latch-up protection is provided for stresses up to 100 mA on address and data pins from –1V to VCC +1V. Doc. No. 3002, Rev. C 2 CAT1161/2 CAPACITANCE TA = 25˚C, f = 1.0 MHz, VCC = 5V Symbol Test Conditions Max Units CI/O(1) Input/Output Capacitance (SDA) VI/O = 0V 8 pF CIN(1) Input Capacitance (SCL) VIN = 0V 6 pF A.C. CHARACTERISTICS VCC=2.7V to 6.0V unless otherwise specified. Output Load is 1 TTL Gate and 100pF. VCC = 2.7V - 6V SYMBOL PARAMETER FSCL Clock Frequency TI(1) Noise Suppresion Time Min VCC = 4.5V - 5.5V Max Min Max Units 100 400 kHz 200 200 ns 3.5 1 µs Constant at SCL, SDA Inputs tAA SLC Low to SDA Data Out and ACK Out tBUF(1) Time the Bus Must be Free Before 4.7 1.2 µs 4 0.6 µs a New Transmission Can Start tHD:STA Start Condition Hold Time tLOW Clock Low Period 4.7 1.2 µs tHIGH Clock High Period 4 0.6 µs tSU:STA Start Condition Setup Time 4.7 0.6 µs (for a Repeated Start Condition) tHD:DAT Data in Hold Time 0 0 ns tSU:DAT Data in Setup Time 50 50 ns tR(1) SDA and SCL Rise Time 1 0.3 µs tF(1) SDA and SCL Fall Time 300 300 ns tSU:STO Stop Condition Setup Time tDH Data Out Hold Time 4 0.6 µs 100 100 ns POWER-UP TIMING (1)(2) Symbol Parameter Max Units tPUR Power-up to Read Operation 1 ms tPUW Power-up to Write Operation 1 ms WRITE CYCLE LIMITS Symbol Parameter tWR Write Cycle Time Min Typ Max Units 10 ms The write cycle time is the time from a valid stop condition of a write sequence to the end of the internal program/erase cycle. During the write cycle, the bus interface circuits are disabled, SDA is allowed to remain high, and the device does not respond to its slave address. NOTE: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) tPUR and tPUW are the delays required from the time VCC is stable until the specific operation can be initiated. 3 Doc No. 3002, Rev. C CAT1161/2 RESET CIRCUIT CHARACTERISTICS Symbol Parameter Min Typ Max Units tGLITCH Glitch Reject Pulse Width 100 ns VRT Reset Threshold Hystersis VOLRS Reset Output Low Voltage (IOLRS=1mA) VOHRS Reset Output High Voltage VCC-0.75 Reset Threshold (VCC=5V) 4.50 4.75 Reset Threshold (VCC=5V) (CAT1161/2-42) 4.25 4.50 Reset Threshold (VCC=3.3V) (CAT1161/2-30) 3.00 3.15 Reset Threshold (VCC=3.3V) (CAT1161/2-28) 2.85 3.00 Reset Threshold (VCC=3V) (CAT1161/2-25) 2.55 2.70 tPURST Power-Up Reset Timeout 130 270 twp Watchdog Period tRPD VTH to RESET Output Delay VRVALID RESET Output Valid 15 mV 0.4 V V (CAT1161/2-45) VTH Doc. No. 3002, Rev. C 1.6 4 ms sec 5 1 V µs V CAT1161/2 PIN DESCRIPTIONS WP: WRITE PROTECT If the pin is tied to VCC the entire memory array becomes Write Protected (READ only). When the pin is tied to GND or left floating normal read/write operations are allowed to the device. RESET outputs. During power-up, the RESET outputs remain active until VCC reaches the VTH threshold and will continue driving the outputs for approximately 200ms (tPURST) after reaching VTH. After the tPURST timeout interval, the device will cease to drive the reset outputs. At this point the reset outputs will be pulled up or down by their respective pull up/ down resistors. During power-down, the RESET outputs will be active when VCC falls below VTH. The RESET outputs will be valid so long as VCC is >1.0V (VRVALID). RESET/RESET RESET: RESET I/O RESET These are open drain pins and can be used as reset trigger inputs. By forcing a reset condition on the pins the device will initiate and maintain a reset condition for approximately 200ms. The RESET pin must be connected through a pull-down resistor, and the RESET pin must be connected through a pull-up resistor. The RESET pins are I/Os; therefore, the CAT1161/2 can act as a signal conditioning circuit for an externally applied manual reset. The inputs are edge triggered; that is, the RESET input in the CAT1161/2 will initiate a reset timeout after detecting a low to high transition and the RESET input will initiate a reset timeout after detecting a high to low transition. SDA: SERIAL DATA ADDRESS The bidirectional serial data/address pin is used to transfer all data into and out of the device. The SDA pin is an open drain output and can be wire-ORed with other open drain or open collector outputs. Watchdog Timer The Watchdog Timer provides an independent protection for microcontrollers. During a system failure, the CAT1161will respond with a reset signal after a time-out interval of 1.6 seconds for a lack of activity. The CAT1161 is designed with the Watchdog Timer feature on the SDA input. If the microcontroller does not toggle the SDA input pin within 1.6 seconds, the Watchdog Timer times out. This will generate a reset condition on reset outputs. The Watchdog Timer is cleared by any transition on SDA. If there is no transition on the SDA for more than 1.6 seconds, the watchdog timer times out. SCL: SERIAL CLOCK Serial clock input. DEVICE OPERATION Reset Controller Description As long as the reset signal is asserted, the Watchdog Timer The CAT1161/2 precision RESET controller ensures will not count and will stay cleared. correct system operation during brownout and power up/down conditions. It is configured with open drain The CAT1162 does not have a Watchdog. t Figure 1. RESET Output Timing GLITCH VTH VRVALID VCC t RPD t PURST t PURST RESET t RPD RESET 5 Doc No. 3002, Rev. C CAT1161/2 Hardware Data Protection falls below (power down) VTH or until VCC reaches the reset threshold (power up) VTH. The CAT1161/2 is designed with the following hardware data protection features to provide a high degree of data integrity. Reset Threshold Voltage The CAT1161/2 is offered with five reset threshold voltage ranges. They are 4.50-4.75V, 4.25-4.50V, 3.003.15V, 2.85-3.00V and 2.55-2.70V. (1) The CAT1161/2 features a WP pin. When the WP pin is tied high the entire memory array becomes write protected (read only). (2) The VCC sense provides write protection when VCC falls below the reset threshold value (VTH). The VCC lock out inhibits writes to the serial EEPROM whenever VCC Figure 2. Bus Timing tF tHIGH tLOW tR tLOW SCL tSU:STA tHD:STA tHD:DAT tSU:DAT tSU:STO SDA IN tAA tBUF tDH SDA OUT Figure 3. Write Cycle Timing SCL SDA 8TH BIT BYTE n ACK tWR STOP CONDITION START CONDITION Figure 4. Start/Stop Timing SDA SCL START BIT Doc. No. 3002, Rev. C STOP BIT 6 ADDRESS CAT1161/2 FUNCTIONAL DESCRIPTION STOP Condition The CAT1161/2 supports the I2C Bus data transmission protocol. This Inter-Integrated Circuit Bus protocol defines any device that sends data to the bus to be a transmitter and any device receiving data to be a receiver. The transfer is controlled by the Master device which generates the serial clock and all START and STOP conditions for bus access. Both the Master device and Slave device can operate as either transmitter or receiver, but the Master device controls which mode is activated. A LOW to HIGH transition of SDA when SCL is HIGH determines the STOP condition. All operations must end with a STOP condition. DEVICE ADDRESSING The Master begins a transmission by sending a START condition. The Master sends the address of the particular slave device it is requesting. The four most significant bits of the 8-bit slave address are fixed as 1010. I2C Bus Protocol The features of the I2C bus protocol are defined as follows: The next three bits (Figure 6) define memory addressing. For the CAT1161/162 the three bits define higher order bits. (1) Data transfer may be initiated only when the bus is not busy. The last bit of the slave address specifies whether a Read or Write operation is to be performed. When this bit is set to 1, a Read operation is selected, and when set to 0, a Write operation is selected. (2) During a data transfer, the data line must remain stable whenever the clock line is high. Any changes in the data line while the clock line is high will be interpreted as a START or STOP condition. After the Master sends a START condition and the slave address byte, the CAT1161/2 monitors the bus and responds with an acknowledge (on the SDA line) when its address matches the transmitted slave address. The CAT1161/2 then performs a Read or Write operation depending on the R/W bit. START Condition The START Condition precedes all commands to the device, and is defined as a HIGH to LOW transition of SDA when SCL is HIGH. The CAT1161/2 monitors the SDA and SCL lines and will not respond until this condition is met. Figure 5. Acknowledge Timing SCL FROM MASTER 1 8 9 DATA OUTPUT FROM TRANSMITTER DATA OUTPUT FROM RECEIVER ACKNOWLEDGE START Figure 6. Slave Address Bits CAT1161/2 CAT 24C163 1 0 1 0 a10 a9 a8 R/W **a8, a9 and a10 correspond to the address of the memory array address word. 7 Doc No. 3002, Rev. C CAT1161/2 ACKNOWLEDGE pointers of the CAT1161/2. After receiving another acknowledge from the Slave, the Master device transmits the data to be written into the addressed memory location. The CAT1161/2 acknowledges once more and the Master generates the STOP condition. At this time, the device begins an internal programming cycle to non-volatile memory. While the cycle is in progress, the device will not respond to any request from the Master device. After a successful data transfer, each receiving device is required to generate an acknowledge. The acknowledging device pulls down the SDA line during the ninth clock cycle, signaling that it received the 8 bits of data. The CAT1161/2 responds with an acknowledge after receiving a START condition and its slave address. If the device has been selected along with a write operation, it responds with an acknowledge after receiving each 8bit byte. Page Write The CAT1161/2 writes up to 16 bytes of data in a single write cycle, using the Page Write operation. The page write operation is initiated in the same manner as the byte write operation, however instead of terminating after the initial byte is transmitted, the Master is allowed to send up to 15 additional bytes. After each byte has been transmitted, the CAT1161/2 will respond with an acknowledge and internally increment the lower order address bits by one. The high order bits remain unchanged. When the CAT1161/2 begins a READ mode it transmits 8 bits of data, releases the SDA line and monitors the line for an acknowledge. Once it receives this acknowledge, the CAT1161/2 will continue to transmit data. If no acknowledge is sent by the Master, the device terminates data transmission and waits for a STOP condition. WRITE OPERATIONS If the Master transmits more than 16 bytes before sending the STOP condition, the address counter ‘wraps around,’ and previously transmitted data will be overwritten. Byte Write In the Byte Write mode, the Master device sends the START condition and the slave address information (with the R/W bit set to zero) to the Slave device. After the Slave generates an acknowledge, the Master sends a 8-bit address that is to be written into the address When all 16 bytes are received, and the STOP condition has been sent by the Master, the internal programming cycle begins. At this point, all received data is written to the CAT1161/2 in a single write cycle. Figure 7. Byte Write Timing BUS ACTIVITY: MASTER SDA LINE S T A R T SLAVE ADDRESS BYTE ADDRESS S T O P DATA S P A C K A C K A C K Figure 8. Page Write Timing BUS ACTIVITY: MASTER SDA LINE S T A R T SLAVE ADDRESS BYTE ADDRESS (n) DATA n+1 S P A C K Doc. No. 3002, Rev. C DATA n S T DATA n+15 O P A C K A C K 8 A C K A C K CAT1161/2 Acknowledge Polling protected and becomes read only. The CAT1161/2 will accept both slave and byte addresses, but the memory location accessed is protected from programming by the device’s failure to send an acknowledge after the first byte of data is received. Disabling of the inputs can be used to take advantage of the typical write cycle time. Once the stop condition is issued to indicate the end of the host’s write opration, the CAT1161/2 initiates the internal write cycle. ACK polling can be initiated immediately. This involves issuing the start condition followed by the slave address for a write operation. If the CAT1161/2 is still busy with the write operation, no ACK will be returned. If a write operation has completed, an ACK will be returned and the host can then proceed with the next read or write operation. Read Operations The READ operation for the CAT1161/2 is initiated in the same manner as the write operation with one exception, that R/W bit is set to one. Three different READ operations are possible: Immediate/Current Address READ, Selective/Random READ and Sequential READ. WRITE PROTECTION The Write Protection feature allows the user to protect against inadvertent memory array programming. If the WP pin is tied to VCC, the entire memory array is Figure 9. Immediate Address Read Timing BUS ACTIVITY: MASTER SDA LINE S T A R T S T O P SLAVE ADDRESS S P A C K DATA N O A C K SCL SDA 8 9 8TH BIT DATA OUT NO ACK 9 STOP Doc No. 3002, Rev. C CAT1161/2 Immediate/Current Address Read Sequential Read The CAT1161/2 address counter contains the address of the last byte accessed, incremented by one. In other words, if the last READ or WRITE access was to address N, the READ immediately following would access data from address N+1. For all devices, N=E=2047. The counter will wrap around to Zero and continue to clock out valid data for the 16K devices. After the CAT1161/ 2 receives its slave address information (with the R/W bit set to one), it issues an acknowledge, then transmits the 8-bit byte requested. The master device does not send an acknowledge, but will generate a STOP condition. The Sequential READ operation can be initiated by either the Immediate Address READ or Selective READ operations. After the CAT1161/2 sends the inital 8-bit byte requested, the Master will responds with an acknowledge which tells the device it requires more data. The CAT1161/2 will continue to output an 8-bit byte for each acknowledge, thus sending the STOP condition. The data being transmitted from the CAT1161/2 is outputted sequentially with data from address N followed by data from address N+1. The READ operation address counter increments all of the CAT1161/2 address bits so that the entire memory array can be read during one operation. If more than E (where E=2047 for the CAT1161/162) bytes are read out, the counter will ‘wrap around’ and continue to clock out data bytes. Selective/Random Read Selective/Random READ operations allow the Master device to select at random any memory location for a READ operation. The Master device first performs a ‘dummy’ write operation by sending the START condition, slave address and byte addresses of the location it wishes to read. After the CAT1161/2 acknowledges, the Master device sends the START condition and the slave address again, this time with the R/W bit set to one. The CAT1161/2 then responds with its acknowledge and sends the 8-bit byte requested. The master device does not send an acknowledge but will generate a STOP condition. Figure 10. Selective Read Timing BUS ACTIVITY: MASTER SDA LINE S T A R T SLAVE ADDRESS S T A R T BYTE ADDRESS (n) S T O P SLAVE ADDRESS S S P A C K A C K A C K DATA n N O A C K Figure 11. Sequential Read Timing BUS ACTIVITY: MASTER SLAVE ADDRESS DATA n DATA n+1 DATA n+2 S T O P DATA n+x SDA LINE P A C K A C K A C K A C K N O A C K Doc. No. 3002, Rev. C 10 CAT1161/2 Ordering Information Prefix CAT Optional Company ID Device # 1162 Product Number 1161: 16K 1162: 16K Suffix J -30 I Temperature Range Blank = Commercial (0˚ to 70˚C) I = Industrial (-40˚ to 85˚C) Package P: PDIP J: SOIC (JEDEC) TE13 Tape & Reel TE13: 2000/Reel Reset Threshold Voltage 45: 4.5-4.75V 42: 4.25-4.5V 30: 3.0-3.15V 28: 2.85-3.0V 25: 2.55-2.7V Note: (1) The device used in the above example is a CAT1162JI-30TE13 (16K I2C Memory, SOIC, Industrial Temperature, 3.0-3.15V Reset Threshold Voltage, Tape and Reel) 11 Doc No. 3002, Rev. C Copyrights, Trademarks and Patents Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: DPP ™ AE2 ™ Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. 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Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete. Catalyst Semiconductor, Inc. Corporate Headquarters 1250 Borregas Avenue Sunnyvale, CA 94089 Phone: 408.542.1000 Fax: 408.542.1200 www.catalyst-semiconductor.com Publication #: Revison: Issue date: Type: 3002 C 09/14/01 Final