hi
how can I modify my code to ensure that both timers start and stop EXACTLY at the same time
I might think about placing T0CON.7=1 and T1CON.7=1 on consecutive lines, depending on your clock you can calculate the instruction cycle delay and calibrate that into your calculations

Depends how "Exactly" fits into your frame of reference, you are measuring pulses on both timers, therefore the difference will always be a constant and you could correct it as a standard systematic error.

Others will probably know of a way to reduce the delay further than I have suggested but ultimately I suggest it depends on the PIC itself.

Does the datasheet give a method of starting two timers with the same instruction?

Just a thought

Duncan