ANALOG DEVICES DS1747W-120+

The DS1747W-120+ is a Y2K compliant, non-volatile timekeeping RAMs in 32 pin EDIP package. This device is a full function, real time clock/calendar (RTC) and 512k x 8 non-volatile static RAM. User access to all registers within the part is accomplished with a byte wide interface. The RTC information and control bits reside in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours, minutes and seconds data in 24 hour binary coded decimal (BCD) format. Corrections for the date of the month and leap year are made automatically. The RTC clock registers are double buffered to avoid access of incorrect data that can occur during clock update cycles and also prevents time loss as the timekeeping countdown continues unabated by access to time register data. This device contains its own power fail circuitry which deselects device when the VCC supply is in out of tolerance condition.