MC68HC08AB16A Datasheet, PDF (171/380 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Timer Interface Module A (TIMA)
Functional Description
11.5.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel
whose output appears on the PTE2/TACH0 pin. The TIMA channel
registers of the linked pair alternately control the pulse width of the
output.
Setting the MS0B bit in TIMA channel 0 status and control register
(TASC0) links channel 0 and channel 1. The TIMA channel 0 registers
initially control the pulse width on the PTE2/TACH0 pin. Writing to the
TIMA channel 1 registers enables the TIMA channel 1 registers to
synchronously control the pulse width at the beginning of the next
PWM period. At each subsequent overflow, the TIMA channel registers
(0 or 1) that control the pulse width are the ones written to last. TASC0
controls and monitors the buffered PWM function, and TIMA channel 1
status and control register (TASC1) is unused. While the MS0B bit is
set, the channel 1 pin, PTE3/TACH1, is available as a general-purpose
I/O pin.
Channels 2 and 3 can be linked to form a buffered PWM channel
whose output appears on the PTF0/TACH2 pin. The TIMA channel
registers of the linked pair alternately control the pulse width of the
output.
Setting the MS2B bit in TIMA channel 2 status and control register
(TASC2) links channel 2 and channel 3. The TIMA channel 2 registers
initially control the pulse width on the PTF0/TACH2 pin. Writing to the
TIMA channel 3 registers enables the TIMA channel 3 registers to
synchronously control the pulse width at the beginning of the next
PWM period. At each subsequent overflow, the TIMA channel registers
(2 or 3) that control the pulse width are the ones written to last. TASC2
controls and monitors the buffered PWM function, and TIMA channel 3
status and control register (TASC3) is unused. While the MS2B bit is
set, the channel 3 pin, PTF1/TACH3, is available as a general-purpose
I/O pin.
NOTE:
In buffered PWM signal generation, do not write new pulse width values
to the currently active channel registers. Writing to the active channel
registers is the same as generating unbuffered PWM signals.
MC68HC08AB16A — Rev. 2.0
MOTOROLA
Timer Interface Module A (TIMA)
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Technical Data
171