How to calculate timer value to use to generate a timer IRQ

Question

I'm using an ARM7 core microcontroller. I'm unsure of how to calculate what T1LD register value to load to the timer to allow it to generate an IRQ every x ms. The only information that I can find in the documentation states "The timer interval is calcualted as follows"

         Interval = ((TxD)xPrescalar)/Source Clock

I'm not sure what the Prescalar, T, and D values are?

Answer 1

Please post your ARM7 model.

Answer 2

My microcontroller is an ADuc7026. (ARM7TDMI Core, 16/32-Bit RISC)