Panasonic MN101C77C, F77G user manual VI 38 Simple Pulse Width Measurement

Chapter 6 8-bit Timers

	Setup Procedure				Description
(7)	Enable the interrupt.			(7)	Set the IRQ2IE flag of the IRQ2ICR register to
	IRQ2ICR (x'3FE4')				"1" to enable the interrupt.
	bp1	:IRQ2IE	= 1
(8)	Enable the timer operation.			(8)	Set the TM0EN flag of the TM0MD register to
	TM0MD (x'3F54')				"1" to enable timer 0 operation.
	bp3	:TM0EN	= 1

TM0BC starts to count up with negative edge of the external interrupt 2 (IRQ2) input as a trigger. Timer 0 continues to count up during "L" period of IRQ2 input, then stop the counting with positive edge of IRQ2 input as a trigger. At the same time, reading the value of TM0BC by interrupt handling can detects "L" period.

VI - 38 Simple Pulse Width Measurement