How to update the timer match register in the program?

Question

Electronics

Hello. I want to implement a similarity of WDT on a conventional timer in the LPC11u12 microcontroller. The bottom line is this: when the timer match is interrupted, it stops, but when the UART receives a byte, the match value resets the timer and (in theory) starts again and everything is fine. What is the problem? This doesn't work, unfortunately.
Is there any possibility to do so at all? If yes, what is the error? If not, what other solutions could there be?

Answer 1

As far as I understand, the counting register of the timer must also be present. We set it to 0 in the UART interrupt, no?
PS Unfortunately, I'm not familiar with LPC11u12. But in AVR I reset the TCNT register.