Panasonic MN101C77C, F77G user manual Simple Pulse Width Measurement

Chapter 6 8-bit Timers

6-9 Simple Pulse Width Measurement

6-9-1 Operation

Timer measures the "L" duration of the pulse signal input from the external interrupt pin.

„Simple Pulse Width Measurement Operation by 8-bit Timer (Timers 0, 4 and 5)

During the input signal of the external interrupt pin (simple pulse width) is "L", the binary counter of the timer counts up. Pulse width "L" period can be measured by reading the count of timer. 8-bit timers that have the simple pulse width measurement function are timers 0, 4 and 5.

Table 6-9-1 Simple Pulse Width Measurement Able Pins (Timers 0, 4 and 5)

	Timer 0	Timer 4	Timer 5
Simple pulse width	External interrupt 2	External interrupt 4	External interrupt 5
measurement enable pin	(P22/IRQ2)	(P24/IRQ4)	(P23/IRQ3)

„Count Timing of Simple Pulse Width Measurement (Timer 0, Timer 4, Timer 5)

Count

clock source

External interrupt IRQ(n/2+2)

TMnEN flag

Compare

regster

FF

Binary	00	01	02	03	04
counter

Figure 6-9-1 Count Timing at Measurement of Simple Pulse Width

(Timer 0, Timer 4, Timer 5))

During the input signal of the external interrupt pin for simple pulse width measurement is "L" at TMnEN flag operation ("1"), timer counts up.

VI - 36 Simple Pulse Width Measurement