11. PPG (Programmable Pulse Generator)
MC97F6108A User’s manual
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PPG (Programmable Pulse Generator)
MC97F6108A has programmable pulse generator (PPG) supporting capture mode operations based
on 16-bit timer. PPG basic function is similar to 16-bit timer's but PPG operates as PWM mode only.
When PPGEN set to '1', PPG output goes to high. And initial value of P05PU(pullup register of PPGO
port) is '1'.
MC97F6108A has five analog comparators, and their output controls PPG operation respectively.
Output from internal comparator 0 whose input is from an external analog pin can be used to
synchronize the pulse output and the pulse controls IGBT.
The PPG
’s
main features are listed below:
One shot pulse.
Comparator 0: When PPGMD=1, Comparator 0 start the PPG.
Comparator 1: Disable the PPG output until flag is cleared.
Comparator 2: Increase or decrease the PPG period in Auto period mode.
Comparator 3: Disable the PPG output (only one period).
Comparator 4: Detect zero crossing
PPGPXH, PPGPXL registers set the maximum period of PPG.
PPG output port(P05) default pullup (P0PU[5] = 1)
PPG default output value is 'high'.
Duty matching reset the PPGO, period matching set the PPGO.
3 comparator interrupt flags are used as PPG capture sources. (CMP3IF, CMP1IF and
CMP4IF).
PPG off time can be controlled by PPG off time min and max registers.
PPG period high/low values are written in the period registers at the same time.
PPG duty high/low values are written in the duty registers at the same time.
It is possible to read and write to the PPG duty and period registers.