Datasheet
© 2011 Microchip Technology Inc. DS70118J-page 89
dsPIC30F2010
14.14 PWM Special Event Trigger
The PWM module has a special event trigger that
allows A/D conversions to be synchronized to the PWM
time base. The A/D sampling and conversion time may
be programmed to occur at any point within the PWM
period. The special event trigger allows the user to min-
imize the delay between the time when A/D conversion
results are acquired, and the time when the duty cycle
value is updated.
The PWM special event trigger has an SFR named
SEVTCMP, and five control bits to control its operation.
The PTMR value for which a special event trigger
should occur is loaded into the SEVTCMP register.
When the PWM time base is in an Up/Down Counting
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
SEVTCMP SFR. If the SEVTDIR bit is cleared, the spe-
cial event trigger will occur on the upward counting
cycle of the PWM time base. If the SEVTDIR bit is set,
the special event trigger will occur on the downward
count cycle of the PWM time base. The SEVTDIR
control bit has no effect unless the PWM time base is
configured for an Up/Down Counting mode.
14.14.1 SPECIAL EVENT TRIGGER
POSTSCALER
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 PWMCON2 SFR.
The special event output postscaler is cleared on the
following events:
• Any write to the SEVTCMP register
• Any device Reset
14.15 PWM Operation During CPU Sleep
Mode
The FLTA input pin has the ability to wake the CPU
from Sleep mode. The PWM module generates an
interrupt if the FLTA
pin is driven low while in Sleep.
14.16 PWM Operation During CPU Idle
Mode
The PTCON 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.