Microchip Technology AC164139 Data Sheet

PIC24FJ256DA210 FAMILY

DS39969B-page 204

 2010 Microchip Technology Inc.

FIGURE 14-2:

OUTPUT COMPARE BLOCK DIAGRAM (DOUBLE-BUFFERED, 16-BIT PWM MODE)

14.3.1

PWM PERIOD

The PWM period is specified by writing to PRy, the
Timer Period register. The PWM period can be
calculated using Equation 14-1.

EQUATION 14-1:

CALCULATING THE PWM PERIOD

(1)

OCxR and

Comparator

OCxTMR

OCxCON1

OCxCON2

OC Output and

OCx Interrupt

OCx Pin

(1)

OCxRS Buffer

Comparator

Fault Logic

Match

Trigger and

Sync Logic

Clock

Select

Increment

Reset

OC Clock
Sources

Trigger and
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>

OCxRS

Event

Rollover

Rollover/Reset

Note 1: The OCx outputs must be assigned to an available RPn pin before use. See Section 10.4 “Peripheral Pin

Select (PPS)” for more information.

2: The OCFA/OCFB fault inputs must be assigned to an available RPn/RPIn pin before use. See Section 10.4

“Peripheral Pin Select (PPS)” for more information.

OCxR and

DCB<1:0>

DCB<1:0> Buffers

Note 1:

Based on T

= T

OSC

* 2; Doze mode and PLL are disabled.

PWM Period = [(PRy) + 1 • T

• (Timer Prescale Value)

where:
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.