1. Home
  2. Embedded Programming
  3. Interrupt not firing on PIC18F

Interrupt not firing on PIC18F

I've started tinkering with a PIC18F4680 (with CAN bus) usin microchips MPLAB C18 C compiler. I've been beating my head against problem for many hours now :evil:

I can't get interrupts to work. I have tried, TMR0, TMR1 and INT0.

have verified that TMRnIP, TMRnIE, TMRnIF and GIEH & IPEN are al HIGH yet my ISR does not get run. If I clear TMRnIF in the main loo TMRnIF is set again when the timer overflows so it appears the time is OK, the ISR just doesn't get run

I have checked the disassembly and there is a goto in 0x08 (the hig

pri interrupt vector) and my ISR at the address GOTOed

Any suggestions what the issue may be

Here is a section of my code

38: RCONbits.IPEN = 1; //enable priorit

level

00003C 8ED0 BSF 0xfd0, 0x7, ACCES 40: IPR1bits.TMR1IP = 1 00003E 809F BSF 0xf9f, 0, ACCES 41: PIR1bits.TMR1IF = 0 000040 909E BCF 0xf9e, 0, ACCES 42: PIE1bits.TMR1IE = 1 000042 809D BSF 0xf9d, 0, ACCES 43: TMR0H = 0; //clear time 000044 6AD7 CLRF 0xfd7, ACCES 44: TMR0L = 0; //clear time 000046 6AD6 CLRF 0xfd6, ACCES 46: INTCONbits.GIEH = 1; //enabl interrupt 00004C 8EF2 BSF 0xff2, 0x7, ACCES 47: 48: T1CONbits.TMR1ON = 0 00004E 90CD BCF 0xfcd, 0, ACCES 49: TMR1H = 0x00 000050 6ACF CLRF 0xfcf, ACCES 50: TMR1L = 0x00 000052 6ACE CLRF 0xfce, ACCES 51: T1CONbits.TMR1ON = 1 000054 80CD BSF 0xfcd, 0, ACCES

67:

//---------------------------------------------------------------------------

68: // High priority interrupt vecto 69: 70: #pragma code HIGH_INTERRUPT_VECTOR = 0x0 71: voi 72: InterruptVectorHigh (void 73: 74: _as 75: goto InterruptHandlerHigh //jump to interrup routin 000008 EF3E GOTO 0x7 00000A F000 NO 76: _endas 77: 00000C 0012 RETURN 78: 79: //--------------------------------------------------------------------------- 80: // High priority interrupt routin 81: 82: #pragma cod 83: #pragma interrupt InterruptHandlerHig 84: 85: voi 86: InterruptHandlerHigh ( 00007C CFDA MOVFF 0xfda, 0xfe 00007E FFE4 NO 000080 CFE2 MOVFF 0xfe2, 0xfd 000082 FFDA NO 000084 52E6 MOVF 0xfe6, F, ACCES 87: 88: // INTCONbits.TMR0IF = 0; //clea interrupt fla 89: Flags.Bit.Timeout = 1; //indicat timeou 000086 0100 MOVLB 000088 8160 BSF 0x60, 0, BANKE 90: LATAbits.LATA0 = !LATAbits.LATA0; //toggle LED o RB 00008A 7089 BTG 0xf89, 0, ACCES 91: // INTCONbits.INT0IF = 0 92: PIR1bits.TMR1IF = 0 00008C 909E BCF 0xf9e, 0, ACCES 93: 00008E 52E5 MOVF 0xfe5, F, ACCES 000090 CFE5 MOVFF 0xfe5, 0xfd 000092 FFDA NO 000094 0011 RETFIE 0x

Any help will something heavy being thrown against my wall. Thanks

Dea

Reply to
namezmud
Loading thread data ...

I have just been bitten by a problem that sounds very similar to this.

I was using the CCS C compiler with a PIC18LF252 and could not get the interrupts to run. Examining the registers showed everything looked "normal" and the overflow bit (it was a serial interrupt) was being set on the second character sent.

After much comparing of files, etc. I found out it was the DEBUG fuse. For some unknown reason, if the DEBUG fuse was set, I got no interrupts. When I cleared the DEBUG fuse, recompiled, and loaded it again, everything worked fine.

According to the part datasheet (even errata), the serial interrupt should not have been affected by the DEBUG fuse. Apparently it is.

Dave

Reply to
starfire

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.