Interrupt doesn't fire

Why doesn't interrupt fire?
SerOut2 shows timer is running.
MPASM
PBP v2.5C
PB PL

Norm

Code:

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' 18F452
                                   
 @ __CONFIG _CONFIG1H, _OSCS_OFF_1H & _HSPLL_OSC_1H
 @ __CONFIG _CONFIG2L, _BORV_45_2L & _BOR_ON_2L & _PWRT_ON_2L
 @ __CONFIG _CONFIG2H, _WDT_ON_2H
 @ __CONFIG _CONFIG4L, _STVR_ON_4L & _LVP_OFF_4L & _DEBUG_OFF_4L


    DEFINE OSC 40 ' REQUIRES PLL  ' USE 10 MHz CRYSTAL & DECLARE: XTAL = 40
    PAUSE 1000  'ALLOW POWER TO STABILIZE 
   
    Clear

    @wTimer1 = TMR1L
    wTimer1 var word EXT   
    LED        VAR        PortA.1
    i VAR WORD
             
    ADCON1 = %00001111  'ALL_DIGITAL

    '********************
    'INTERRUPT REGISTER'S
    wTIMER1 = 0
    RCON.7 = 0  ' 0 DISABLES PRIORITY LEVELS ON INTERRUPTS (16F COMPATABILITY)
    T1CON = %10000001  '%xx00xxx = 1:1 PRESCALE
    PIE1 = %00000001    'enable TMR1 overflow interrupt
    INTCON = %11000000  'enable global and peripheral interrupts   
    '********************
   
    TRISA.5 = 0
    TRISA.4 = 1                     
    TRISA.3 = 1
    TRISA.2 = 0
    TRISA.1 = 0 
    TRISA.0 = 0
    TRISB=%00000000
    TRISC=%00010000  ' xxx1xxxx MSSP SPI data in
    TRISD=%00000000
    TRISE.2 = 1
    TRISE.1 = 1
    TRISE.0 = 1
                               
     
ON INTERRUPT GoTo SET_PORT_INTERRUPT
GOTO MAIN
   
   
'**** INTURRUPT ROUTINE ****   
Disable        ' Disable interrupts during interrupt handler
SET_PORT_INTERRUPT:

SerOut2 PORTA.2,16416,["SET_PORT_INTERRUPT",13]
TOGGLE LED     
wTimer1 = 500

INTCON.2 = 0    ' Reset timer interrupt flag
Resume
'**** END INTURRUPT ROUTINE **** 

   
MAIN:

FOR i = 1 TO 100
PAUSE 10
NEXT

SerOut2 PORTA.2,16416,["MAIN LOOP  wTimer1 = ",DEC wTimer1,13]
'              16416 = 19200 

GOTO MAIN
END

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Hi Norm,

You have interrupt checking disabled. Add ENABLE after RESUME in your interrupt handler.

Also PIR1.0 is the Timer1 interrupt flag bit. Not INTCON.2....;o}

Works good.

Require fastest interrupt.

Does this interrupt execute at end of current command or does it immediately
jump to the interrupt handler?

Main code will follow a "Repeat : Until wTIMER1 < 65500" so interrupt cannot disrupt.

Norm

With ON INTERRUPT it only checks for an interrupt condition and jumps to your interrupt
handler after each PBP command has finished. If you need fast reaction times to
interrupts, use DTs' interrupt code or use assembler interrupts.

FYI: With Timer1 in 16-bit read/write mode, you don't want to use EXT to create your word
to read/write Timer1. EXT works on the low byte first, then the high byte.

With RD16 set, to write to Timer1, you write to TMR1H first, then write to TMR1L. Reading
Timer1 with RD16 set, you read TMR1L first, then read TMR1H.

In 8-bit mode EXT will work fine. In 16-bit mode it won't since you're always writing to and
reading low byte first.

Fastest Interrupt?

Code:

---

   
'18F452

 @ __CONFIG _CONFIG1H, _OSCS_OFF_1H & _HSPLL_OSC_1H
 @ __CONFIG _CONFIG2L, _BORV_45_2L & _BOR_ON_2L & _PWRT_ON_2L
 @ __CONFIG _CONFIG2H, _WDT_ON_2H
 @ __CONFIG _CONFIG4L, _STVR_ON_4L & _LVP_OFF_4L & _DEBUG_OFF_4L

    DEFINE OSC 40 ' REQUIRES PLL  ' USE 10 MHz CRYSTAL & DECLARE: XTAL = 40
    PAUSE 1000  'ALLOW POWER TO STABILIZE 
   
    Clear
 
    LED        VAR        PortA.1
    i VAR WORD 
    wREAD_TR1 VAR WORD
    wWRITE_TR1 VAR WORD
    wWRITE_TR1 = 1000
         
    ADCON1 = %00001111  'ALL_DIGITAL

    '********************
    'INTERRUPT REGISTER'S
    RCON.7 = 0  ' 0 DISABLES PRIORITY LEVELS ON INTERRUPTS (16F COMPATIBILITY)
'    T1CON = %10000001  '%xx00xxx = 1:1 PRESCALE
    T1CON = %10110001  '%xx00xxx = 1:8 PRESCALE                       
    PIE1 = %00000001    'enable TMR1 overflow interrupt
    INTCON = %11000000  'enable global and peripheral interrupts   
    '********************
   
    TRISA.5 = 0
    TRISA.4 = 1                     
    TRISA.3 = 1
    TRISA.2 = 0
    TRISA.1 = 0 
    TRISA.0 = 0
    TRISB=%00000000
    TRISC=%00010000  ' xxx1xxxx MSSP SPI data in
    TRISD=%00000000
    TRISE.2 = 1
    TRISE.1 = 1
    TRISE.0 = 1
                               
' Define interrupt handler
DEFINE  INTHAND myint

GOTO MAIN

'**** ASSEMBLY INTERRUPT ROUTINE **** 
Asm
myint
EndAsm

'SerOut2 PORTA.2,16416,["SET_PORT_INTERRUPT",13]
TOGGLE LED
TMR1H = wWRITE_TR1.HIGHBYTE
TMR1L = wWRITE_TR1.LOWBYTE 

Asm
    bcf    PIR1, 0                        ; Clear interrupt flag
    retfie                              ; Return from interrupt
EndAsm
'**** END ASSEMBLY INTURRUPT ROUTINE ****   
   
   
MAIN:
'wWRITE_TR1 = 32000
wWRITE_TR1 = 500

FOR i = 1 TO 1000
PAUSE 1
NEXT

REPEAT
    wREAD_TR1.LOWBYTE = TMR1L
    wREAD_TR1.HIGHBYTE = TMR1H
UNTIL wREAD_TR1 < 50000  'TMR1 NON INTERFEARANCE WITH SEROUT2 

SerOut2 PORTA.2,16416,["MAIN LOOP wREAD = ",DEC wREAD_TR1,13]
'              16416 = 19200
GOTO MAIN


END

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