Motorola MVME187 User Manual

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Functional Description
2-17
2
Battery Backed Up RAM and Clock
The MK48T08 RAM and clock chip is a 28-pin package that 
provides 
A time-of-day clock
An oscillator
A crystal
Power fail detection
Memory write protection
8KB of RAM
A battery
The clock provides
Seconds, minutes, hours, day, date, month, and year in BCD 
24-hour format
Automatic corrections for 28-, 29- (leap year), and 30-day 
months
No interrupts are generated by the clock. 
The MK48T08 is an 8 bit device; however, the interface provided by 
the PCCchip2 supports 8-, 16-, and 32-bit accesses to the MK48T08.
Refer to the MK48T08 data sheet for detailed programming 
information.