DSPIC30F6010A MICROCHIP [Microchip Technology], DSPIC30F6010A Datasheet - Page 87

• Manufacturer Part Number: DSPIC30F6010A
• Description: High-Performance, 16-bit Digital Signal Controllers
• Manufacturer: MICROCHIP [Microchip Technology]

13.4.2
The PWM period is specified by writing to the PRx
register. The PWM period can be calculated using
Equation
EQUATION 13-1:
PWM frequency is defined as 1/[PWM period].
FIGURE 13-2:
© 2011 Microchip Technology Inc.
PWM Period = [(PRx) + 1] • 4 • T
13-1.
PWM PERIOD
OCxR = OCxRS
TMR3 = PR3
(Interrupt Flag)
T3IF = 1
PWM PERIOD
(TMRx Prescale Value)
PWM OUTPUT TIMING
Duty Cycle
TMR3 = Duty Cycle (OCxR)
OSC
Period
•
OCxR = OCxRS
TMR3 = PR3
(Interrupt Flag)
T3IF = 1
dsPIC30F6010A/6015
When the selected TMRx is equal to its respective
period register, PRx, the following four events occur on
the next increment cycle:
• TMRx is cleared.
• The OCx pin is set.
• The PWM duty cycle is latched from OCxRS into
• The corresponding timer interrupt flag is set.
See
Timer3 is referred to in the figure for clarity.
TMR3 = Duty Cycle (OCxR)
- Exception 1: If PWM duty cycle is 0x0000,
- Exception 2: If duty cycle is greater than PRx,
OCxR.
the OCx pin will remain low.
the pin will remain high.
Figure 13-2
for key PWM period comparisons.
DS70150E-page 87