mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 389

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor, Inc.
Timer Interface Module A (TIMA-6)
Functional Description
NOTE:
In PWM signal generation, do not program the PWM channel to toggle
on output compare. Toggling on output compare prevents reliable
0 percent 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 TIMA status control register (TASC), clear the TIMA stop bit,
TSTOP.
Setting MS0B links channels 0 and 1 and configures them for buffered
PWM operation. The TIMA channel 0 registers (TACH0H–TACH0L)
initially control the buffered PWM output. TIMA status control register 0
(TASC0) 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 TIMA channel 2 registers (TACH2H–TACH2L)
initially control the PWM output. TIMA status control register 2 (TASC2)
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 TIMA channel 4 registers (TACH4H–TACH4L)
initially control the PWM output. TIMA status control register 4 (TASC4)
controls and monitors the PWM signal from the linked channels. MS4B
takes priority over MS4A.
Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on
TIMA overflows. Subsequent output compares try to force the output to
a state it is already in and have no effect. The result is a 0 percent duty
cycle output.
Setting the channel x maximum duty cycle bit (CHxMAX) and clearing
the TOVx bit generates a 100 percent duty cycle output. (See
22.9.4
TIMA Channel Status and Control
Registers.)
MC68HC908AS60 — Rev. 1.0
Technical Data
Timer Interface Module A (TIMA-6)
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