Microchip Technology dsPIC30F - Page 290

dsPIC30F Family Reference Manual
DS70061C-page 14-8 © 2004 Microchip Technology Inc.
Example 14-1: Compare Mode Toggle Mode Pin State Setup
Example 14-2 shows example code for the configuration and interrupt service of the Single
Compare mode toggle event.
Example 14-2: Compare Mode Toggle Setup and Interrupt Servicing
; The following code example illustrates how to define the initial
; OC1 pin state for the output compare toggle mode of operation.
; Toggle mode with initial OC1 pin state set low
MOV 0x0001, w0 ; load setup value into w0
MOV w0, OC1CON ; enable module for OC1 pin low, toggle high
BSET OC1CON, #1 ; set module to toggle mode with initial pin
; state low
; Toggle mode with initial OC1 pin state set high
MOV 0x0002, w0 ; load setup value into w0
MOV w0, OC1CON ; enable module for OC1 pin high, toggle low
BSET OC1CON, #0 ; set module to toggle mode with initial pin
; state high
; The following code example will set the Output Compare 1 module
; for interrupts on the toggle event and select Timer 2 as the clock
; source for the compare time-base. It is assumed in that Timer 2
; and Period Register 2 are properly configured. Timer 2 will
; be enabled here.
CLR OC1CON ; Turn off Output Compare 1 Module.
MOV #0x0003, w0 ; Load the working register with the new
MOV w0, OC1CON ; compare mode and write to OC1CON
MOV #0x0500, w0 ; Initialize Compare Register 1
MOV w0, OC1R ; with 0x0500
BSET IPC0, #OC1IP0 ; Setup Output Compare 1 interrupt for
BCLR IPC0, #OC1IP1 ; desired priority level
BCLR IPC0, #OC1IP2 ; (this example assigns level 1 priority)
BCLR IFS0, #OC1IF ; Clear Output Compare 1 interrupt flag
BSET IEC0, #OC1IE ; Enable Output Compare 1 interrupts
BSET T2CON, #TON ; Start Timer2 with assumed settings
; Example code for Output Compare 1 ISR:
__OC1Interrupt:
BCLR IFS0, #OC1IF ; Reset respective interrupt flag
; Remaining user code here
RETFIE ; Return from ISR