W85C178 Datasheet PDF – Real Time Clock IC – Winbond

Part Number: W85C178

Function: Real Time Clock With 128-Byte RAM

Package: DIP 24P

Manufacturer: Winbond


W85C178 Real Time Clock


The Real Time Clock with 128-byte RAM is a peripheral device for use with various microprocessors. The W85C178 is designed to be a direct replacement for the MC146818A. The device’s function include a time-of-day clock, an alarm, a one-hundred-year calendar, a square wave generator, programmable interrupts, and 114 bytes of nonvolatile static RAM. The device uses CMOS technology and interfaces with most microprocessor buses. The device consumes very little power.


W85C178 datasheet


1. 14 bytes of clock and control / status registers
2. 128 bytes of general nonvolatile storage
3. BCD or binary representation of time, calendar, and alarm registers
4. Counts seconds, minutes, hours, days of the week, days of the month, momths, years
5. 12-hour to 24-hour clock with AM and PM in 12-hour mode
6. Daylight saving time option
7. Automatic leap-year adjustment
8. Programmable square wave output signal
7. Time base input option : 4.194304 MHz, 1.048576 MHz, 32.768 kHz
8. Automatic end of month recognition


Other data sheets are available within the file: MC146818A, 85C178

W85C178 Datasheet PDF Download

W85C178 pdf

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