MC68HC912B32 Datasheet, PDF (67/128 Pages) Motorola, Inc – 16-Bit Microcontroller

PPOL3 — PWM Channel 3 Polarity
0 = Channel 3 output is low at the beginning of the clock cycle; high when the duty count is reached.
1 = Channel 3 output is high at the beginning of the clock cycle; low when the duty count is reached.
PPOL2 — PWM Channel 2 Polarity
0 = Channel 2 output is low at the beginning of the clock cycle; high when the duty count is reached.
1 = Channel 2 output is high at the beginning of the clock cycle; low when the duty count is reached.
PPOL1 — PWM Channel 1 Polarity
0 = Channel 1 output is low at the beginning of the clock cycle; high when the duty count is reached.
1 = Channel 1 output is high at the beginning of the clock cycle; low when the duty count is reached.
PPOL0 — PWM Channel 0 Polarity
0 = Channel 0 output is low at the beginning of the clock cycle; high when the duty count is reached.
1 = Channel 0 output is high at the beginning of the clock cycle; low when the duty count is reached.
Depending on the polarity bit, the duty registers may contain the count of either the high time or the low
time. If the polarity bit is zero and left alignment is selected, the duty registers contain a count of the low
time. If the polarity bit is one, the duty registers contain a count of the high time. For center-aligned op-
eration the high or low time is multiplied by two.
PWEN — PWM Enable
$0042
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
PWEN3 PWEN2 PWEN1 PWEN0
RESET:
0
0
0
0
0
0
0
0
Setting any of the PWENx bits causes the associated port P line to become an output regardless of the
state of the associated data direction register (DDRP) bit. This does not change the state of the data
direction bit. When PWENx returns to zero, the data direction bit controls I/O direction. On the front end
of the PWM channel, the scaler clock is enabled to the PWM circuit by the PWENx enable bit being
high. When all four PWM channels are disabled, the prescaler counter shuts off to save power. There
is an edge-synchronizing gate circuit to guarantee that the clock will only be enabled or disabled at an
edge.
Read and write anytime.
PWEN3 — PWM Channel 3 Enable
The pulse modulated signal will be available at port P, bit 3 when its clock source begins its next cycle.
0 = Channel 3 is disabled.
1 = Channel 3 is enabled.
PWEN2 — PWM Channel 2 Enable
The pulse modulated signal will be available at port P, bit 2 when its clock source begins its next cycle.
0 = Channel 2 is disabled.
1 = Channel 2 is enabled.
PWEN1 — PWM Channel 1 Enable
The pulse modulated signal will be available at port P, bit 1 when its clock source begins its next cycle.
0 = Channel 1 is disabled.
1 = Channel 1 is enabled.
PWEN0 — PWM Channel 0 Enable
The pulse modulated signal will be available at port P, bit 0 when its clock source begins its next cycle.
0 = Channel 0 is disabled.
1 = Channel 0 is enabled.
MC68HC912B32
MC68HC912B32TS/D
MOTOROLA
67