The Real Time Clock (RTC) is a clock-calendar IP core that keeps track of the “Time of Day”.  The core is organized as a series of BCD counters that counts Seconds, Minutes, Hours, Days, Months and Years (Time Units). 

The RTC seconds counter time base is generated from a clock input that is separate from the system clock.  The time-base for the seconds counter is nominally 32.768 kHz.  To aid in precision, there is programmable terminal count (divisor) for this clock.   Calibration accuracy is controlled by software.


  • Clock / Calendar (BCD Format)
  • Seconds
  • Minutes
  • Hours
  • Days
  • Months
  • Years
  • Alarm Mode for each “Time Unit”
  • Repeat Alarm Mode for each “Time Unit”
  • AMBA APB Interface
  • Interrupt control for Alarms


  • Verilog Source
  • Complete Test Environment
  • AHB Bus Functional Model
  • C-Sample Code