mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 362

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

Chapter 11 Pulse Width Modulator with Fault Protection (PMF15B6CV2)
11.4.5.2
The IPOLx bits select either the odd or the even PWM value registers to use in the next PWM cycle.
To detect the current status, the voltage on each ISx pin is sampled twice in a PWM period, at the end of
each deadtime. The value is stored in the DTx bits in the PMF Deadtime Sample register (PMFDTMS).
The DTx bits are a timing marker especially indicating when to toggle between PWM value registers.
Software can then set the IPOLx bit to toggle PMFVAL registers according to DTx values.
362
Manual Correction
IPOLx bits are buffered so only one PWM register is used per PWM cycle.
If an IPOLx bit changes during a PWM period, the new value does not take
effect until the next PWM period.
IPOLx bits take effect at the end of each PWM cycle regardless of the state
of the load okay bit, LDOK.
PWM CONTROLLED BY EVEN
PWM CYCLE START
IPOLA
IPOLB
IPOLC
Bit
Figure 11-54. Internal Correction Logic when ISENS = 01
ODD PWMVALREGISTER
PWM CONTROLLED BY
PWMVAL REGISTER
IPOLx BIT
Table 11-48. Top/Bottom Manual Correction
Logic Atate
0
1
0
1
0
1
MC9S12E256 Data Sheet, Rev. 1.08
D
CLK
Q
PMFVAL0 controls PWM0/PWM1 pair
PMFVAL1 controls PWM0/PWM1 pair
PMFVAL2 controls PWM2/PWM3 pair
PMFVAL3 controls PWM2/PWM3 pair
PMFVAL4 controls PWM4/PWM5 pair
PMFVAL5 controls PWM4/PWM5 pair
A
B
NOTE
A/B
GENERATOR
DEADTIME
Output Control
BOTTOM PWM
TOP PWM
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