mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 353

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

12.3.2.2
The starting polarity of each PWM channel waveform is determined by the associated PPOLx bit in the
PWMPOL register. If the polarity bit is 1, the PWM channel output is high at the beginning of the cycle
and then goes low when the duty count is reached. Conversely, if the polarity bit is 0 the output starts low
and then goes high when the duty count is reached.
Read: anytime
Write: anytime
Freescale Semiconductor
Module Base + 0x0001
PPOL3
PPOL2
PPOL1
PPOL0
Reset
Field
3
2
1
0
W
R
Pulse Width Channel 3 Polarity
0 PWM channel 3 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 3 output is high at the beginning of the period, then goes low when the duty count is reached.
Pulse Width Channel 2 Polarity
0 PWM channel 2 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 2 output is high at the beginning of the period, then goes low when the duty count is reached.
Pulse Width Channel 1 Polarity
0 PWM channel 1 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 1 output is high at the beginning of the period, then goes low when the duty count is reached.
Pulse Width Channel 0 Polarity
0 PWM channel 0 output is low at the beginning of the period, then goes high when the duty count is reached
1 PWM channel 0 output is high at the beginning of the period, then goes low when the duty count is reached.
PWM Polarity Register (PWMPOL)
0
0
7
PPOLx register bits can be written anytime. If the polarity is changed while
a PWM signal is being generated, a truncated or stretched pulse can occur
during the transition
= Unimplemented or Reserved
0
0
6
Figure 12-4. PWM Polarity Register (PWMPOL)
Table 12-2. PWMPOL Field Descriptions
0
5
MC9S12Q128
Rev 1.09
NOTE
0
4
Chapter 12 Pulse-Width Modulator (PWM8B4C) Block Description
Description
PPOL3
0
3
PPOL2
0
2
PPOL1
0
1
PPOL0
0
0
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