Panasonic F77G Cell Phone User Manual


 
VII - 27
Chapter 7 16-bit Timer
16-bit High Precision PWM Output
7-7 16-bit High Precision PWM Output
(Cycle/Duty can be changed consecutively)
The TM7IO pin outputs high precision PWM output, which is determined by the match timing of the timer
binary counter and the compare register 1 and the match timing of the binary counter and the compare
register 2.
7-7-1 Operation
16-bit High Precision PWM Output Operation (Timer 7)
The PWM waveform with any cycle/duty is generated by setting the cycle of PWM to the compare
register 1 (TM7OC1) and setting the duty of the "H" period to the compare register 2 (TM7OC2). The 16-
bit timer that high precision PWM output operation function can be used is timer 7.
Count Timing of High Precision PWM Output (at Normal) (Timer 7)
Figure 7-7-1 Count Timing of High Precision PWM Output (at Normal)
PWM source waveform,
(A) is "H" until the binary counter reaches the compare register from x'0000'.
(B) is "L" after the TM7OC2 compare match, then the binary counter counts up till the
binary counter reaches the TM7OC1 compare register to be cleared.
(C) is "H", again if the binary counter is cleared.
The PWM output from pin is 1 count clock delay of PWM source waveform. This is happened to form
inside to correct the output cycle.
N
M+1 M+2 N-1
N
Count
clock
TM7EN
flag
Compare
register 1
Binary
counter
0000 0001 M+1M-1
M
0000 0001 M-1
M
TM7IO output
(PWM output)
PWM basic component (Set time in the compare register 1)
Set time in the compare register 2
PWM source
waveform
(A)
(B)
(C)
M
Compare
register 2