mc68hc708mp16 Freescale Semiconductor, Inc, mc68hc708mp16 Datasheet - Page 151

• Manufacturer Part Number: mc68hc708mp16
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

MC68HC708MP16
Freescale Semiconductor
NOTE:
—
Rev. 3.1
To correct deadtime distortion, software can decrease or increase the
value in the appropriate PWMVAL register.
In complementary channel operation, the ISENS1–3 bits in PWM control
register 1 select one of three correction methods:
The ISENSx bits are not buffered; therefore, changing the current
sensing method can affect the present PWM cycle.
ISENS[1:0]
1. The polarity of the ISx pin is latched when both the top and bottom PWMs are off. At the
2. Current is sensed even with 0% or 100% duty cycle.
Pulse Width Modulator for Motor Control (PWMMC)
•
•
•
•
•
0% and 100% duty cycle boundaries, there is no deadtime, so no new current value is
sensed.
0X
10
11
In edge-aligned operation, decreasing or increasing the PWM
value by a correction value equal to the deadtime compensates for
deadtime distortion.
In center aligned operation, decreasing or increasing the PWM
value by a correction value equal to one-half the deadtime
compensates for deadtime distortion.
Manual correction
Automatic current-sensing correction during deadtime
Automatic current sensing correction when the PWM counter
value equals the value in the PWM counter modulus registers.
Manual correction with IPOL1–IPOL3 bits; or for no correction
Automatic current-sensing correction on pins IS1, IS2, and IS3
during deadtime
Automatic current-sensing correction on pins IS1, IS2, and IS3
Table 9-4. Correction Method Selection
At the half cycle in center-aligned operation
At the end of the cycle in edge-aligned operation
(1)
Pulse Width Modulator for Motor Control (PWMMC)
Correction method
Technical Data
(2)
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