Microchip Technology MA240029 データシート
PIC24FJ128GA310 FAMILY
DS39996F-page 214
2010-2011 Microchip Technology Inc.
FIGURE 15-2:
OUTPUT COMPARE BLOCK DIAGRAM (DOUBLE-BUFFERED, 16-BIT PWM MODE)
15.3.1
PWM PERIOD
The PWM period is specified by writing to PRy, the
Timer Period register. The PWM period can be
calculated using
Timer Period register. The PWM period can be
calculated using
.
EQUATION 15-1:
CALCULATING THE PWM PERIOD
(1)
Comparator
OCxTMR
OCxCON1
OCxCON2
OCx Interrupt
OCx Pin
(1)
OCxRS Buffer
Comparator
Match
Match
Trigger and
Sync Logic
Clock
Select
Increment
Reset
OC Clock
Sources
Sources
Trigger and
Sync Sources
Sync Sources
Reset
Match Event
OCFA/OCFB
(2)
OCTSELx
SYNCSELx
TRIGSTAT
TRIGMODE
OCTRIG
OCMx
OCINV
OCTRIS
FLTOUT
FLTTRIEN
FLTMD
ENFLT<2:0>
OCFLT<2:0>
OCINV
OCTRIS
FLTOUT
FLTTRIEN
FLTMD
ENFLT<2:0>
OCFLT<2:0>
OCxRS
Event
Event
Rollover
Rollover/Reset
Rollover/Reset
Note 1:
The OCx outputs must be assigned to an available RPn pin before use. See
for more information.
2:
The OCFA/OCFB Fault inputs must be assigned to an available RPn/RPIn pin before use. See
for more information.
OCxR and
DCB<1:0>
DCB<1:0>
OCxR and
DCB<1:0> Buffers
OC Output and
Fault Logic
Note 1:
Based on T
CY
= T
OSC
* 2; Doze mode and PLL are disabled.
PWM Period = [(PRy) + 1 • T
CY
• (Timer Prescale Value)
where:
PWM Frequency = 1/[PWM Period]
PWM Frequency = 1/[PWM Period]
Note:
A PRy value of N will produce a PWM period of N + 1 time base count cycles. For example, a value of
7, written into the PRy register, will yield a period consisting of 8 time base cycles.
7, written into the PRy register, will yield a period consisting of 8 time base cycles.