mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 365

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

To calculate the output duty cycle (high time as a % of period) for a particular channel:
Read: anytime
Write: anytime
Freescale Semiconductor
Module Base + 0x0018
Module Base + 0x0019
Module Base + 0x001A
Module Base + 0x001B
Reset
Reset
Reset
Reset
•
•
•
W
W
W
W
R
R
R
R
Polarity = 0 (PPOLx = 0)
Polarity = 1 (PPOLx = 1)
For boundary case programming values, please refer to
Duty cycle = [(PWMPERx–PWMDTYx)/PWMPERx] * 100%
Duty cycle = [PWMDTYx / PWMPERx] * 100%
Bit 7
Bit 7
Bit 7
Bit 7
1
1
1
1
7
7
7
7
Depending on the polarity bit, the duty registers will contain the count of
either the high time or the low time. If the polarity bit is 1, the output starts
high and then goes low when the duty count is reached, so the duty registers
contain a count of the high time. If the polarity bit is 0, the output starts low
and then goes high when the duty count is reached, so the duty registers
contain a count of the low time.
Figure 12-23. PWM Channel Duty Registers (PWMDTY0)
Figure 12-24. PWM Channel Duty Registers (PWMDTY1)
Figure 12-25. PWM Channel Duty Registers (PWMDTY2)
Figure 12-26. PWM Channel Duty Registers (PWMDTY3)
6
1
6
1
6
1
6
1
6
6
6
6
5
1
5
1
5
1
5
1
5
5
5
5
MC9S12Q128
Rev 1.09
NOTE
4
1
4
1
4
1
4
1
4
4
4
4
Chapter 12 Pulse-Width Modulator (PWM8B4C) Block Description
Section 12.4.2.8, “PWM Boundary Cases.”
3
1
3
1
3
1
3
1
3
3
3
3
2
1
2
1
2
1
2
1
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
Bit 0
Bit 0
Bit 0
Bit 0
1
1
1
1
0
0
0
0
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