Interrupt not firing on PIC18F

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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

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
00004C    8EF2     BSF 0xff2, 0x7, ACCES
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

<< snip >


68:                // High priority interrupt vecto
70:                #pragma code HIGH_INTERRUPT_VECTOR = 0x0
71:                voi
72:                InterruptVectorHigh (void
74:                  _as
75:                    goto InterruptHandlerHigh //jump to interrup
000008    EF3E     GOTO 0x7
00000A    F000     NO
76:                  _endas
00000C    0012     RETURN
80:                // High priority interrupt routin
82:                #pragma cod
83:                #pragma interrupt InterruptHandlerHig
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
88:                //  INTCONbits.TMR0IF = 0;            //clea
interrupt fla
89:                  Flags.Bit.Timeout = 1;            //indicat
000086    0100     MOVLB
000088    8160     BSF 0x60, 0, BANKE
90:                  LATAbits.LATA0 = !LATAbits.LATA0; //toggle LED o
00008A    7089     BTG 0xf89, 0, ACCES
91:                //  INTCONbits.INT0IF = 0
92:                    PIR1bits.TMR1IF = 0
00008C    909E     BCF 0xf9e, 0, ACCES
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


Re: Interrupt not firing on PIC18F
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

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


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