PIC——MCC18 interrupt writing method

The high priority interrupt entry address of the PIC18 series is at 0x0008. The following code places a vector function at this entry address. This vector function contains an embedded assembly GOTO instruction, which GOTOs to the high priority interrupt service function InterruptHandlerHigh.

//----------------------------High priority interrupt entry-----------------------------------

1 #pragma code InterruptVectorHigh = 0x08 //Use the #pragma pseudo-instruction to define a segment named InterruptVectorHigh, and put this segment in the code space starting at address 0x08
 2 void InterruptVectorHigh (void) //High priority interrupt vector function
 3 {
 4 _asm
 5 goto InterruptHandlerHigh //Embedded assembly instruction
 6 _endasm
 7 }
 8 #pragma code //Return to the default code segment, the reason is the same as above
 9 #pragma interrupt InterruptHandlerHigh 
10 
11 void InterruptHandlerHigh (void)
12 {
13 /* The code of the high priority service function is written here*/
14 
15 if (INTCONbits.TMR0IF)
16 {//check for TMR0 overflow
17 INTCONbits.TMR0IF = 0; //clear interrupt flag
18 ;
19 ;
20 }
21 } 

For MPLAB C18, the high-priority and low-priority interrupt vector functions and interrupt service functions can only appear once each, and there cannot be multiple interrupt service functions. If multiple interrupts are of high priority, the high-priority interrupt service function performs corresponding processing by judging their respective interrupt flag bits.

CONbits.IPEN = 1; //Enable interrupt priority
INTCONbits.GIEH = 1; //Enable/disable all high priority interrupts
INTCONbits.GIEL = 1; //Enable/disable all low priority interrupts

//RCONbits.IPEN = 0; //Disable interrupt priority
//INTCONbits.GIE = ​​1; //Enable/disable all interrupt sources
//INTCONbits.PEIE = 1; //Enable/disable all peripheral interrupt sources


When IPEN=1, the interrupt source uses high priority interrupt GIEH = 1; GIEL = 0;
when the interrupt source uses low priority interrupt GIEH = 1; GIEL = 1;

when IPEN=0, all interrupts jump to 08H (use high priority interrupt vector entry)
GIEH = 1; GIEL = 1;