Datasheet

 2012 Microchip Technology Inc. Preliminary DS41637B-page 241
PIC16(L)F1784/6/7
24.3.9 ECCP COMPATIBLE FULL-BRIDGE
PWM
This mode of operation is designed to match the
Full-Bridge mode from the ECCP module. It is called
ECCP compatible as the term “full-bridge” alone has
different connotations in regards to the output
waveforms.
Full-Bridge Compatible mode uses the same
waveform events as the single PWM mode to gener-
ate the output waveforms.
There are both Forward and Reverse modes available
for this operation, again to match the ECCP implemen-
tation. Direction is selected with the mode control bits.
24.3.9.1 Mode Features
• Dead-band control available on direction switch
- Changing from forward to reverse uses the
falling edge dead-band counters.
- Changing from reverse to forward uses the
rising edge dead-band counters.
• No steering control available
• PWM is output on the following four pins only:
- PSMCxA
- PSMCxB
- PSMCxC
- PSMCxD
24.3.9.2 Waveform Generation – Forward
In this mode of operation, three of the four pins are
static. PSMCxA is the only output that changes based
on rising edge and falling edge events.
S
tatic Signal Assignment
• Outputs set to active state
- PSMCxD
• Outputs set to inactive state
- PSMCxB
- PSMCxC
Rising Edge Event
• PSMCxA is set active
Falling Edge Event
• PSMCxA is set inactive
24.3.9.3 Waveform Generation – Reverse
In this mode of operation, three of the four pins are
static. Only PSMCxB toggles based on rising edge
and falling edge events.
Static Signal Assignment
• Outputs set to active state
- PSMCxC
• Outputs set to inactive state
- PSMCxA
- PSMCxD
Rising Edge Event
• PSMCxB is set active
Falling Edge Event
• PSMCxB is set inactive
FIGURE 24-12: ECCP COMPATIBLE FULL-BRIDGE PWM WAVEFORM – PSMCXSTR0 = 0FH
1 2 3 4 5 6 7 8 9 10 11 12
Rising Edge Dead Band
Falling Edge Dead Band
Forward mode operation
PWM Period Number
Period Event
Falling Edge Event
Reverse mode operation
PSMCxA
PSMCxB
PSMCxC
PSMCxD