The CDP68HC68T1 Real-Time Clock provides a time/calendar function, a 32 byte static RAM, and a 3 wire Serial Peripheral Interface (SPI Bus). The primary function of the clock is to divide down a frequency input that can be supplied by the on-board oscillator in conjunction with an external crystal or by an external clock source.

FEATUREs
• SPI (Serial Peripheral Interface)
• Full Clock Features
   - Seconds, Minutes, Hours (12/24, AM/PM), Day of
      Week, Date, Month, Year (0-99), Automatic Leap Year
• 32 Word x 8-Bit RAM
• Seconds, Minutes, Hours Alarm
• Automatic Power Loss Detection
• Low Minimum Standby (Timekeeping) Voltage . . . . . 2.2V
• Selectable Crystal or 50/60Hz Line Input
• Buffered Clock Output
• Battery Input Pin that Powers Oscillator and also
   Connects to VDD Pin When Power Fails
• Three Independent Interrupt Modes
   - Alarm
   - Periodic
   - Power-Down Sense