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Chapter 7 16-bit Timer
16-bit Standard PWM Output
7-6 16-bit Standard PWM Output
(Only duty can be changed consecutively)
The TM7IO pin outputs the standard PWM output, which is determined by the over flow timing of the
binary counter, and the match timing of the timer binary counter and the compare register.
7-6-1 Operation
16-bit Standard PWM Output (Timer 7)
PWM waveform with an arbitrary duty is generated by setting a duty of PWM "H" period to the compare
register 1 (TM7OC1). Its cycle is the time of the 16-bit timer full count over flow.
Table 7-6-1 shows the PWM output pin.
Table 7-6-1 PWM Output Pin
Count Timing of Standard PWM Output (at Normal)(Timer 7)
Figure 7-6-1 Count Timing of Standard PWM Output (at Normal)
PWM source waveform,
(A) shows "H" till the binary counter reaches the compare register from x'0000'.
(B) shows "L" after the compare match, then the binary counter counts up till the over flow.
(C) shows "H", again if the binary counter becomes overflow.
The PWM output form pins is 1 count clock delay of PWM source waveform. This is happened to
correct the output cycle.
N
N+1 N+2 FFFE
FFFF
Count
clock
TM7EN
flag
Compare
register 1
Binary
counter
0000 0001 N+1N-1
N
0000 0001 N-1
N
TM7IO output
(PWM output)
PWM basic component (overflow time of the binary counter)
Setup time for compare register 1
PWM source
waveform
(A)
(B)
(C)
Timer 7
TM7IO output pin
(P14)
PWM output pin