Panasonic F77G shows the clock source that can be selected, Clock Source at Timer OperationTimer

Chapter 7 16-bit Timer

Table 7-3-2 shows the clock source that can be selected.

Table 7-3-2 Clock Source at Timer Operation(Timer 7)

Clock source	1 count time
fosc	50 ns
fosc/2	100 ns
fosc/4	200 ns
fosc/16	800 ns
fs	100 ns
fs/2	200 ns
fs/4	400 ns
fs/16	1.6 ∝s
Notes : as fosc = 20 MHz	fx = 32.768 kHz fs
= fosc/2 = 10 MHz

„Count Timing of Timer Operation (Timer 7)

The binary counter counts up with the selected clock source as the count clock. The basic operation of the whole function of 16-bit timer is as follows ;

Count
clock
TM7EN
flag
Preset		N	M
register
	(A)	(C)
Compare		N	M
register
	(A)		(D)
Binary	0000	0001 0002	N-1 N 0000 0001 0002	0003
counter
	(A)	(B)		(E)
Interrupt
request flag

Figure 7-3-1 Count Timing of Timer Operation (Timer 7)

(A)When any data is written to the preset register as the TM7EN flag is stopped ("0"), the same value is loaded at the writing cycle and the binary counter is cleared to x'0000'.

(B)If the TM7EN flag is "1", the binary counter starts counting. The counting is happened at the falling edge of the count clock.

16-bit Timer Count VII - 11