MSP430FR5043: RTC interrupt

Hi Anburaja,

Due to the divisions being binary (2,4, 8 etc.) I do not think you'll be able to get 5s exactly. You can set an interrupt on the 1s interval and increment a counter and then do your process on the 5th count. The example code on the RTC Counter mode may assist here.

Another option would be to use a Timer and set the clock source for the timer to be ACLK (32.768 kHz clock) and divide this clock using the ID and/or IDEX registers to divide this clock value down. You can then set the capture compare register (CCRx) to the value that would equal 5s.

Here's some example math:
Equation: CCR value = Timer Period * Timer Clock Frequency - 1.

If we divide ACLK by 4, we get Timer CLK Frequency = 8192 Hz, TimerPeriod = 5s. So the CCR value would be set to (8192 * 5) - 1 =  0x9FFF (hex) or 40959 (decimal).

Here is the Timer example code to assist.

Regards,
Luke