Technical data

MOTOROLA MC68HC912B32

68 MC68HC912B32TS/D

PWPRES is a free-running 7-bit counter. Read anytime. Write only in special mode (SMOD = 1).

Read and write anytime. A write will cause the scaler counter PWSCNT0 to load the PWSCAL0 value

unless in special mode with DISCAL = 1 in the PWTST register.

PWM channels 0 and 1 can select clock S0 (scaled) as its input clock by setting the control bit PCLK0

and PCLK1 respectively. Clock S0 is generated by dividing clock A by the value in the PWSCAL0 reg-

ister and dividing again by two. When PWSCAL0 = $00, clock A is divided by 256 then divided by two

to generate clock S0.

PWSCNT0 is a down-counter that, upon reaching $00, loads the value of PWSCAL0. Read any time.

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 reg-

ister and dividing again by two. When PWSCAL1 = $00, 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.

PWPRES — PWM Prescale Counter $0043

Bit 7 6 5 4 3 2 1 Bit 0

0 Bit 6 5 4 3 2 1 Bit 0

RESET: 0 0 0 0 0 0 0 0

PWSCAL0 — PWM Scale Register 0 $0044

Bit 7 6 5 4 3 2 1 Bit 0

RESET: 0 0 0 0 0 0 0 0

PWSCNT0 — PWM Scale Counter 0 Value $0045

Bit 7 6 5 4 3 2 1 Bit 0

RESET: 0 0 0 0 0 0 0 0

PWSCAL1 — PWM Scale Register 1 $0046

Bit 7 6 5 4 3 2 1 Bit 0

RESET: 0 0 0 0 0 0 0 0

PWSCNT1 — PWM Scale Counter 1 Value $0047

Bit 7 6 5 4 3 2 1 Bit 0

RESET: 0 0 0 0 0 0 0 0