MC68HC08AS32 Datasheet, PDF (217/394 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Timer Interface (TIM)
Functional Description
4. In TIM channel x status and control register (TSCx):
a. Write 0–1 (for unbuffered output compare or PWM signals) or
1–0 (for buffered output compare or PWM signals) to the
mode select bits, MSxB–MSxA. (See Table 16-3.)
b. Write 1 to the toggle-on-overflow bit, TOVx.
c. Write 1–0 (to clear output on compare) or 1–1 (to set output
on compare) to the edge/level select bits, ELSxB–ELSxA. The
output action on compare must force the output to the
complement of the pulse width level. (See Table 16-3.)
NOTE:
In PWM signal generation, do not program the PWM channel to toggle
on output compare. Toggling on output compare prevents reliable 0%
duty cycle generation and removes the ability of the channel to
self-correct in the event of software error or noise. Toggling on output
compare can also cause incorrect PWM signal generation when
changing the PWM pulse width to a new, much larger value.
5. In the TIM status control register (TSC), clear the TIM stop bit,
TSTOP.
Setting MS0B links channels 0 and 1 and configures them for buffered
PWM operation. The TIM channel 0 registers (TCH0H–TCH0L) initially
control the buffered PWM output. TIM status control register 0 (TSC0)
controls and monitors the PWM signal from the linked channels. MS0B
takes priority over MS0A.
Setting MS2B links channels 2 and 3 and configures them for buffered
PWM operation. The TIM channel 2 registers (TCH2H–TCH2L) initially
control the PWM output. TIM status control register 2 (TSC2) controls
and monitors the PWM signal from the linked channels. MS2B takes
priority over MS2A.
Setting MS4B links channels 4 and 5 and configures them for buffered
PWM operation. The TIM channel 4 registers (TCH4H–TCH4L) initially
control the PWM output. TIM status control register 4 (TSC4) controls
and monitors the PWM signal from the linked channels. MS4B takes
priority over MS4A.
MC68HC08AS32 — Rev. 3.0
MOTOROLA
Timer Interface (TIM)
Advance Information
217