X1240 Datasheet | Xicor

DESCRIPTION 2-Wire RTC FEATURES - 2-Wire Interface interoperable with I2C. - 400k Hz data transfer rate - Secondary Power Supply Input with internal switch-over circuitry. - Year 2000 pliant - 2K bytes of EEPROM - 64 Byte Page Write Mode - 3 bit Block Lock - Low Power CMOS - <1µA Operating Current - <3m A Active Current during Program - <400µA Active Current during Data Read - Single Byte Write Capability - Typical Nonvolatile Write Cycle Time: 5ms - High Reliability - 1,000,000 Endurance Cycles - Guaranteed Data Retention: 100 Years - Small Package Options - 8-Lead SOIC Package, 8L TSSOP Package The X1240 is a Real Time Clock with clock/calendar circuits. The dual port clock register allows the clock to operate, without loss of accuracy, even during read and write operations. The clock/calendar provides functionality that is controllable and readable through a set of registers. The clock, using a low cost 32.768k Hz crystal input, accurately tracks the time in seconds, minutes, hours, date, day, month and years. It has leap year correction, automatic adjustment for the year 2000 and months with less than 31 days. The device offers a backup power input pin. This Vback pin allows the device to be backed up by a nonrechargeable battery. The RTC is fully operational from 1.8 to 5.5 volts. The X1240 provides a 2K byte EEPROM array, giving a safe, secure memory for critical user and configuration data. This memory is unaffected by plete failure of the main and backup supplies. BLOCK DIAGRAM 32.768k Hz X1 Oscillator X2 Frequency Divider 1Hz Timer Calendar Logic Time Keeping Registers (SRAM) SCL SDA Serial Interface Decoder Control Decode Logic Control Registers (EEPROM) Status Register (SRAM) 16K EEPROM Array ©Xicor, Inc. 1994, 1995, 1996, 1997, 1998, 1999 Patents Pending 9900-3003.5 12/6/99 CM Characteristics subject to change without notice PIN CONFIGURATION X1240 8 pin SOIC X1 X2 NC VSS 1 2 3 4 8 7 6 5 VCC VBack SCL SDA 10M 220K X1 X2 Figure 1. Remended...