mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 384

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 12 Pulse-Width Modulator (PWM8B6CV1)
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
384
PWME1
PWME0
PPOL5
PPOL4
PPOL3
Reset
Field
Field
1
0
5
4
3
W
R
Pulse Width Channel 1 Enable
0 Pulse width channel 1 is disabled.
1 Pulse width channel 1 is enabled. The pulse modulated signal becomes available at PWM, output bit 1 when
Pulse Width Channel 0 Enable
0 Pulse width channel 0 is disabled.
1 Pulse width channel 0 is enabled. The pulse modulated signal becomes available at PWM, output bit 0 when
Pulse Width Channel 5 Polarity
0 PWM channel 5 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 5 output is high at the beginning of the period, then goes low when the duty count is reached.
Pulse Width Channel 4 Polarity
0 PWM channel 4 output is low at the beginning of the period, then goes high when the duty count is reached.
1 PWM channel 4 output is high at the beginning of the period, then goes low when the duty count is reached.
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.
PWM Polarity Register (PWMPOL)
0
0
7
its clock source begins its next cycle.
its clock source begins its next cycle. If CON01 = 1, then bit has no effect and PWM output line 0 is disabled.
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
Table 12-2. PWME Field Descriptions (continued)
Figure 12-4. PWM Polarity Register (PWMPOL)
Table 12-3. PWMPOL Field Descriptions
PPOL5
MC9S12E256 Data Sheet, Rev. 1.08
0
5
PPOL4
NOTE
0
4
Description
Description
PPOL3
3
0
PPOL2
0
2
PPOL1
Freescale Semiconductor
0
1
PPOL0
0
0