I need to measure the elapsed time between two events.

Basically I have two pulses. We will call them pulse A and Pulse B.

Pulse A is a 5v pulse that goes low for about 1600us, about every 3500us.
Pulse B is a 5v pulse that goes low for about 600us during the time that pulse A is low.

I need to measure the time between when pulse B goes low to the time pulse A goes high with an acuracy of at least 1us. The value will be between <1us, and 1600us. I will be using a 22.1184MHz Crystal

I would like to start timer1 in mode 1 when pulse B goes low with an interupt.
I would like to stop timer1 and store its value in a table when pulse a goes high. When the table has reached its desired length, store the average for further computation. The table needs to be of an adjustable length, and be a FIFO configuration.

Can I use the state of any pin as an interupt, or am I limited to INT0, and INT1. If so(state of any pin)how?

How do I create a data table?

Your Help is greatly appreciated.

Chris Seeley