DS1644LPM

The DS1644L is a low profile module that requires a PLCC surface mountable socket and is functionally equivalent to the DS1644. The DS1644L is a 32K x 8 nonvolatile static RAM with a full function real time clock which are both accessible in a Byte¤Cwide format.Th real time clock information resides in the eight upper-most RAM locations. The RTC registers DS1644L contain year,month, date, day, hours, minutes, and seconds data in 24 hour BCD format. Corrections for the day of the month and leap year are made automatically. The RTC clock registers DS1644L are double buffered to avoid access of in-correct data that can occur during clock update cycles.The double buffered system also prevents time loss as the timekeeping countdown continues unabated by ac-cess to time register data. The DS1644L also contains its own power-fail circuitry which deselects the devic supply is in an out¤Cof-tolerance cond when the V_CC tion. This feature prevents loss of data from unpredict-able system operation brought on by low V_CCas errant access and update cycles are avoided.