I'm looking for a creative solution or any ideas for a method of measuring the time between to rising edge interrupts using only pin B0 of an 877a chip.

I've basically got an external PWM signal that I am monitoring using a B0 pin interupt using the "Instant Interrupts" that Daryl created (Great by the way). The interupt is triggered on the rising edge and processes a small subroutine before exiting the interrupt. After exiting the interupt the PIC processes other code while it looks for the next rising interupt. The interupt and subroutine work great, but I need to know how often the interrupt occurs.

I have not tried this yet, but I was thinking of using the COUNT command to count the number of pulses over a certain period of time, but I am not sure if the COUNT command will work and not be effected by the interrupt.

I apreciate any input.