Microchip Technology dsPIC30F - Page 304

dsPIC30F Family Reference Manual
DS70061C-page 14-22 © 2004 Microchip Technology Inc.
Example 14-6 shows configuration and interrupt service code for the PWM mode of operation.
Example 14-6: PWM Mode Pulse Setup and Interrupt Servicing
; The following code example will set the Output Compare 1 module
; for PWM mode w/o FAULT pin enabled, a 50% duty cycle and a
; PWM frequency of 52.08 kHz at Fosc = 40 MHz. Timer2 is selected as
; the clock for the PWM time base and Timer2 interrupts
; are enabled.
CLR OC1CON ; Turn off Output Compare 1 Module.
MOV #0x0060, w0 ; Initialize Duty Cycle to 0x0060
MOV w0, OC1RS ; Write duty cycle buffer register
MOV w0, OC1R ; Write OC1R to initial duty cycle value
MOV #0x0006, w0 ; Load the working register with the new
MOV w0, OC1CON ; compare mode and write to OC1CON
MOV #0x00BF w0 ; Initialize PR2 with 0x00BF
MOV w0, PR2 ;
BSET IPC0, #T2IP0 ; Setup Timer 2 interrupt for
BCLR IPC0, #T2IP1 ; desired priority level
BCLR IPC0, #T2IP2 ; (this example assigns level 1 priority)
BCLR IFS0, #T21IF ; Clear Timer 2 interrupt flag
BSET IEC0, #T21IE ; Enable Timer 2 interrupts
BSET T2CON, #TON ; Start Timer2 with assumed settings
; Example code for Timer 2 ISR:
__T2Interrupt:
BCLR IFS0, #T21IF ; Reset respective interrupt flag
; Remaining user code here
RETFIE ; Return from ISR