16-BIT DATA BUS
PWMA REGISTER
PWMB REGISTER
PWMBUFA REGISTER PWMBUFB REGISTER
COMPARATOR A
COMPARATOR B
7
R
LATCH
S
R
LATCH
S
PWMB
PIN
PWMA
PIN
F1A
BIT
F1B
BIT
ZERO DETECTOR
ZERO DETECTOR
SFA
BIT
SFB
BIT
MULTIPLEXER A
MULTIPLEXER B
16-BIT COUNTER
16-BIT TIMER BUS
FROM
PRESCALER
16/32 PWM BLOCK
Figure 7-6 PWM Block Diagram
7.11.1 PWM Counter
The 16-bit counter in the PWM unit is similar to the timer counter in the capture/com-
pare unit. During reset, the GPT is configured to use the system clock divided by two
to drive the counter. Initialization software can reconfigure the counter to use one of
seven prescaler outputs or an external clock input from the PCLK pin.
MOTOROLA
7-16
GENERAL-PURPOSE TIMER
MC68331
USER’S MANUAL
MOTOROLA [ MOTOROLA ]
