.....Donald.

Yes IF the low 8 bits of thr reload constant are 00h AND the worst case time, due to all factors that result in interrupt latency, is less than 256 ticks of the timer clock.

(Some systems with multiple interrupts could see more than 256 time ticks of interrupt latency, especially if those other ISRs had any amount of code in them OR if the mainline code had significant periods where interrupts were disabled.

Michael Karas