Pulse-Width Modulation (PWM) Module
29-13
Freescale Semiconductor
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
29.3
Functional Description
29.3.1
PWM Clock Select
There are four available clocks—clock A, B, SA (scaled A), and SB (scaled B)—all based on the internal
bus clock.
Clock A and B can be programmed to run at 1, 1/2,..., 1/128 times the internal bus clock. Clock SA and
SB use clock A and B respectively as an input and divide it further with a reloadable counter. The rates
available for clock SA and SB are programmable to run at clock A and B divided by 2, 4,..., or 512. Each
PWM channel has the capability of selecting one of two clocks, the prescaled clock (clock A or B) or the
scaled clock (clock SA or SB). The block diagram in
shows the four different clocks and how
the scaled clocks are created.
1
PWM7IL
PWM channel 7 input polarity. If PWMSDN[SDNEN] is set, this bit sets the active level of the PWM 7 channel
0 PWM 7 input is active low
1 PWN 7 input is active high
0
SDNEN
PWM emergency shutdown enable. If set, the pin associated with PWM channel 7 is forced to input and the
emergency shutdown feature is enabled.
0 Emergency shutdown is disabled
1 Emergency shutdown is enabled
Table 29-13. PWMSDN Field Descriptions (continued)
Field
Description
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
