CHAPTER 7 8-BIT TIMER/EVENT COUNTERS 50 AND 51
Preliminary User’s Manual U19014EJ1V0UD
191
(1) PWM output basic operation
Setting
<1> Set each register.
•
Clear the port output latch (P17 or P33)
Note
and port mode register (PM17 or PM33)
Note
to 0.
•
TCL5n: Select the count clock.
•
CR5n: Compare
value
•
TMC5n: Stop the count operation, select PWM mode.
The timer output F/F is not changed.
TMC5n1
Active Level Selection
0 Active-high
1 Active-low
Timer output enabled
(TMC5n = 01000001B or 01000011B)
<2> The count operation starts when TCE5n = 1.
Clear TCE5n to 0 to stop the count operation.
Note
8-bit timer/event counter 50: P17, PM17
8-bit timer/event counter 51: P33, PM33
PWM output operation
<1> PWM output (output from TO5n) outputs an inactive level until an overflow occurs.
<2> When an overflow occurs, the active level is output. The active level is output until CR5n matches the count
value of 8-bit timer counter 5n (TM5n).
<3> After the CR5n matches the count value, the inactive level is output until an overflow occurs again.
<4> Operations <2> and <3> are repeated until the count operation stops.
<5> When the count operation is stopped with TCE5n = 0, PWM output becomes inactive.
For details of timing, see
Figures 7-14
and
7-15
.
The cycle, active-level width, and duty are as follows.
•
Cycle = 2
8
t
•
Active-level width = Nt
•
Duty = N/2
8
(N = 00H to FFH)
Remark
n = 0, 1
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