Interrupt not firing on PIC18F

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

I can't get interrupts to work.  I have tried, TMR0, TMR1 and INT0.  I
have verified that TMRnIP, TMRnIE, TMRnIF and GIEH & IPEN are all
HIGH yet my ISR does not get run.  If I clear TMRnIF in the main loop
TMRnIF is set again when the timer overflows so it appears the timer
is OK, the ISR just doesn't get run.

I have checked the disassembly and there is a goto in 0x08 (the high
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 priority
levels
00003C    8ED0     BSF 0xfd0, 0x7, ACCESS
40:                  IPR1bits.TMR1IP = 1;
00003E    809F     BSF 0xf9f, 0, ACCESS
41:                  PIR1bits.TMR1IF = 0;
000040    909E     BCF 0xf9e, 0, ACCESS
42:                  PIE1bits.TMR1IE = 1;
000042    809D     BSF 0xf9d, 0, ACCESS
43:                  TMR0H = 0;                    //clear timer
000044    6AD7     CLRF 0xfd7, ACCESS
44:                  TMR0L = 0;                    //clear timer
000046    6AD6     CLRF 0xfd6, ACCESS
46:                  INTCONbits.GIEH = 1;          //enable
interrupts
00004C    8EF2     BSF 0xff2, 0x7, ACCESS
47:                
48:                  T1CONbits.TMR1ON = 0;
00004E    90CD     BCF 0xfcd, 0, ACCESS
49:                  TMR1H = 0x00;
000050    6ACF     CLRF 0xfcf, ACCESS
50:                  TMR1L = 0x00;
000052    6ACE     CLRF 0xfce, ACCESS
51:                  T1CONbits.TMR1ON = 1;
000054    80CD     BSF 0xfcd, 0, ACCESS


<< snip >>

67:               
//----------------------------------------------------------------------------
68:                // High priority interrupt vector
69:                
70:                #pragma code HIGH_INTERRUPT_VECTOR = 0x08
71:                void
72:                InterruptVectorHigh (void)
73:                {
74:                  _asm
75:                    goto InterruptHandlerHigh //jump to interrupt
routine
000008    EF3E     GOTO 0x7c
00000A    F000     NOP
76:                  _endasm
77:                }
00000C    0012     RETURN 0
78:                
79:               
//----------------------------------------------------------------------------
80:                // High priority interrupt routine
81:                
82:                #pragma code
83:                #pragma interrupt InterruptHandlerHigh
84:                
85:                void
86:                InterruptHandlerHigh ()
00007C    CFDA     MOVFF 0xfda, 0xfe4
00007E    FFE4     NOP
000080    CFE2     MOVFF 0xfe2, 0xfda
000082    FFDA     NOP
000084    52E6     MOVF 0xfe6, F, ACCESS
87:                {
88:                //  INTCONbits.TMR0IF = 0;            //clear
interrupt flag
89:                  Flags.Bit.Timeout = 1;            //indicate
timeout
000086    0100     MOVLB 0
000088    8160     BSF 0x60, 0, BANKED
90:                  LATAbits.LATA0 = !LATAbits.LATA0; //toggle LED on
RB0
00008A    7089     BTG 0xf89, 0, ACCESS
91:                //  INTCONbits.INT0IF = 0;
92:                	PIR1bits.TMR1IF = 0;
00008C    909E     BCF 0xf9e, 0, ACCESS
93:                }
00008E    52E5     MOVF 0xfe5, F, ACCESS
000090    CFE5     MOVFF 0xfe5, 0xfda
000092    FFDA     NOP
000094    0011     RETFIE 0x1

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

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

"namezmud" <drtroake@hotmail-dot-com.no-spam.invalid> wrote in message 
news:bsKdnQMfGuoMpYHfRVn_vA@giganews.com...
> I've started tinkering with a PIC18F4680 (with CAN bus) using
> microchips MPLAB C18 C compiler.  I've been beating my head against a
> problem for many hours now :evil: .
>
> I can't get interrupts to work.  I have tried, TMR0, TMR1 and INT0.  I
> have verified that TMRnIP, TMRnIE, TMRnIF and GIEH & IPEN are all
> HIGH yet my ISR does not get run.  If I clear TMRnIF in the main loop
> TMRnIF is set again when the timer overflows so it appears the timer
> is OK, the ISR just doesn't get run.
>
> I have checked the disassembly and there is a goto in 0x08 (the high
> 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 priority
> levels
> 00003C    8ED0     BSF 0xfd0, 0x7, ACCESS
> 40:                  IPR1bits.TMR1IP = 1;
> 00003E    809F     BSF 0xf9f, 0, ACCESS
> 41:                  PIR1bits.TMR1IF = 0;
> 000040    909E     BCF 0xf9e, 0, ACCESS
> 42:                  PIE1bits.TMR1IE = 1;
> 000042    809D     BSF 0xf9d, 0, ACCESS
> 43:                  TMR0H = 0;                    //clear timer
> 000044    6AD7     CLRF 0xfd7, ACCESS
> 44:                  TMR0L = 0;                    //clear timer
> 000046    6AD6     CLRF 0xfd6, ACCESS
> 46:                  INTCONbits.GIEH = 1;          //enable
> interrupts
> 00004C    8EF2     BSF 0xff2, 0x7, ACCESS
> 47:
> 48:                  T1CONbits.TMR1ON = 0;
> 00004E    90CD     BCF 0xfcd, 0, ACCESS
> 49:                  TMR1H = 0x00;
> 000050    6ACF     CLRF 0xfcf, ACCESS
> 50:                  TMR1L = 0x00;
> 000052    6ACE     CLRF 0xfce, ACCESS
> 51:                  T1CONbits.TMR1ON = 1;
> 000054    80CD     BSF 0xfcd, 0, ACCESS
>
>
> << snip >>
>
> 67:
> //----------------------------------------------------------------------------
> 68:                // High priority interrupt vector
> 69:
> 70:                #pragma code HIGH_INTERRUPT_VECTOR = 0x08
> 71:                void
> 72:                InterruptVectorHigh (void)
> 73:                {
> 74:                  _asm
> 75:                    goto InterruptHandlerHigh //jump to interrupt
> routine
> 000008    EF3E     GOTO 0x7c
> 00000A    F000     NOP
> 76:                  _endasm
> 77:                }
> 00000C    0012     RETURN 0
> 78:
> 79:
> //----------------------------------------------------------------------------
> 80:                // High priority interrupt routine
> 81:
> 82:                #pragma code
> 83:                #pragma interrupt InterruptHandlerHigh
> 84:
> 85:                void
> 86:                InterruptHandlerHigh ()
> 00007C    CFDA     MOVFF 0xfda, 0xfe4
> 00007E    FFE4     NOP
> 000080    CFE2     MOVFF 0xfe2, 0xfda
> 000082    FFDA     NOP
> 000084    52E6     MOVF 0xfe6, F, ACCESS
> 87:                {
> 88:                //  INTCONbits.TMR0IF = 0;            //clear
> interrupt flag
> 89:                  Flags.Bit.Timeout = 1;            //indicate
> timeout
> 000086    0100     MOVLB 0
> 000088    8160     BSF 0x60, 0, BANKED
> 90:                  LATAbits.LATA0 = !LATAbits.LATA0; //toggle LED on
> RB0
> 00008A    7089     BTG 0xf89, 0, ACCESS
> 91:                //  INTCONbits.INT0IF = 0;
> 92:                PIR1bits.TMR1IF = 0;
> 00008C    909E     BCF 0xf9e, 0, ACCESS
> 93:                }
> 00008E    52E5     MOVF 0xfe5, F, ACCESS
> 000090    CFE5     MOVFF 0xfe5, 0xfda
> 000092    FFDA     NOP
> 000094    0011     RETFIE 0x1
>
> Any help will something heavy being thrown against my wall.  Thanks.
> Dean
>