The UCD3138x has an internal real time clock (RTC) function that can track time in seconds, minutes, hours and days. This function requires an external precision 10 MHz clock.
- Firmware writable time/day register which tracks the total number of days.
- The day counter will be able to count 4 years worth of days.
- Years and months and leap year calculation must be calculated in firmware.
- Firmware programmable frequency correction of ±200 ppm in 0.8 ppm steps
- The RTC function can provide interrupts to the IRQ or FIQ at 1, 10, 30, and 60 second intervals.
- The clock from the RTC driver can be driven to an external pin through an internal multiplexor
- The clock for the RTC function can come from an external clock through a dedicated GPIO pin.