MC912DG128A Motorola, MC912DG128A Datasheet - Page 180

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

PWSCAL1 — PWM Scale Register 1
PWSCNT1 — PWM Scale Counter 1 Value
PWCNTx — PWM Channel Counters
Pulse-Width Modulator
MC68HC912DT128A Rev 2.0
180
PWCNT0
PWCNT1
PWCNT2
PWCNT3
RESET:
RESET:
RESET:
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
0
0
0
6
6
0
6
6
0
6
6
6
6
6
0
Read and write anytime. A write will cause the scaler counter PWSCNT1
to load the PWSCAL1 value unless in special mode with DISCAL = 1 in
the PWTST register.
PWM channels 2 and 3 can select clock S1 (scaled) as its input clock by
setting the control bit PCLK2 and PCLK3 respectively. Clock S1 is
generated by dividing clock B by the value in the PWSCAL1 register + 1
and dividing again by two. When PWSCAL1 = $FF, clock B is divided by
256 then divided by two to generate clock S1.
PWSCNT1 is a down-counter that, upon reaching $00, loads the value
of PWSCAL1. Read any time.
Read and write anytime. A write will cause the PWM counter to reset to
$00.
In special mode, if DISCR = 1, a write does not reset the PWM counter.
5
5
5
5
5
0
5
5
0
5
5
0
Pulse-Width Modulator
4
4
4
4
4
0
4
4
0
4
4
0
3
3
3
3
3
0
3
3
0
3
3
0
2
2
2
2
2
0
2
2
0
2
2
0
1
1
1
1
1
0
1
1
0
1
1
0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
0
0
0
MOTOROLA
$004A
$004B
$0048
$0049
$0046
$0047
10-pwm