DSPIC33FJ12MC202 Microchip Technology Inc., DSPIC33FJ12MC202 Datasheet - Page 155

• Manufacturer Part Number: DSPIC33FJ12MC202
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

14.16 PWM Special Event Trigger
The PWM module has a Special Event Trigger that
allows ADC conversions to be synchronized to the
PWM time base. The ADC sampling and conversion
time can be programmed to occur at any point within
the PWM period. The Special Event Trigger allows the
programmer to minimize the delay between the time
when ADC conversion results are acquired and the
time when the duty cycle value is updated.
The PWM Special Event Trigger has an SFR named
PxSECMP, and five control bits to control its operation.
The PxTMR value for which a Special Event Trigger
should occur is loaded into the PxSECMP register.
When the PWM time base is in Up/Down Count mode,
an additional control bit is required to specify the
counting phase for the Special Event Trigger. The
count phase is selected using the SEVTDIR control bit
in the PxSECMP SFR:
• If the SEVTDIR bit is cleared, the Special Event
• If the SEVTDIR bit is set, the Special Event Trig-
The SEVTDIR control bit has no effect unless the PWM
time base is configured for an Up/Down Count mode.
© 2007 Microchip Technology Inc.
Trigger occurs on the upward counting cycle of
the PWM time base.
ger occurs on the downward count cycle of the
PWM time base.
Preliminary
dsPIC33FJ12MC201/202
14.16.1
The PWM Special Event Trigger has a postscaler that
allows a 1:1 to 1:16 postscale ratio. The postscaler is
configured by writing the SEVOPS<3:0> control bits in
the PWMxCON2 SFR.
The special event output postscaler is cleared on the
following events:
• Any write to the PxSECMP register
• Any device Reset
14.17 PWM Operation During CPU Sleep
The Fault A and Fault B input pins can wake the CPU
from Sleep mode. The PWM module generates an
interrupt if either of the Fault pins is driven low while in
Sleep mode.
14.18 PWM Operation During CPU Idle
The PxTCON SFR contains a PTSIDL control bit. This
bit determines if the PWM module will continue to
operate or stop when the device enters Idle mode. If
PTSIDL = 0, the module will continue to operate. If
PTSIDL = 1, the module will stop operation as long as
the CPU remains in Idle mode.
Mode
Mode
SPECIAL EVENT TRIGGER
POSTSCALER
DS70265B-page 153