Instant Interrupts - Revisited

[WOZZY-2010]

Hi,

I've been trying vary to fully understand the RBC_INT interrupt handler in DT_INTS-18.pbp.

So I wrote this little program, Created a simulator circuit model and also a similar hardware circuit.

Here is the Code:

' RBC TEST.BAS
' PIC 18F6480
' MPLAB IDE V8.40
' PBP V2.60
' Build Options: [-ampasmwin]
' RB4  Momentary Contact Button Goes High on Press,  10K Resistor to Ground
' RB5  Momentary Contact Button Goes High on Press,  10K Resistor to Ground
' RB6  Momentary Contact Button Goes High on Press,  10K Resistor to Ground
' RB7  Momentary Contact Button Goes High on Press,  10K Resistor to Ground
' RC6  22K ohm to RX on 57600-N-8-1 Serial Terminal

INCLUDE "DT_INTS-18.bas"		; Include Darrel Taylor's Base Interrupt System for PIC18F [Version:3.4 (NOV 04, 2009)]

DEFINE OSC 20
DEFINE DEBUG_REG PORTC	
DEFINE DEBUG_BIT 6 			
DEFINE DEBUG_BAUD 57600
DEFINE DEBUG_MODE 1 
DEFINE  SHOWDIGITAL 1

TRISB=%11111111
ADCON0=%00000000
ADCON1=%00001111

BTN	  VAR	BYTE

ASM
INT_LIST  macro ; IntSource,  Label,      Type,  ResetFlag?
        INT_Handler RBC_INT, _DO_RBC_INT,   ASM,  yes	
    endm
    INT_CREATE
ENDASM

@  INT_ENABLE   RBC_INT

DEBUG "INTERRUPT CREATED",10,13
DEBUG "INTERRUPT ENABLED",10,13

HOLD_HERE:
DEBUG "WAITING FOR INTERRUPT",10,13
PAUSE 2500
GOTO HOLD_HERE

DO_RBC_INT
DEBUG "############### RBC INTERRUPT ACTIVATED #################",10,13

MENU:
PAUSE 200
DEBUG "MENU - READ BUTTONS",10,13
If PORTB.4 = 1 Then PAUSE 250: Goto DO_ENABLE
If PORTB.5 = 1 Then PAUSE 250: Goto DO_DISABLE
If PORTB.6 = 1 Then PAUSE 250: Goto DO_RETURN
If PORTB.7 = 1 Then PAUSE 250: Goto DO_CLEAR
GOTO MENU

DO_ENABLE:
DEBUG "RUNNING DO_ENABLE",10,13
@ INT_ENABLE RBC_INT
Pause 250
GOTO HOLD_HERE

DO_DISABLE:
DEBUG "RUNNING DO_DISABLE",10,13
@ INT_DISABLE RBC_INT
PAUSE 250
GOTO HOLD_HERE

DO_RETURN:
DEBUG "RUNNING DO_RETURN",10,13
@ INT_RETURN
PAUSE 250
GOTO HOLD_HERE

DO_CLEAR:
DEBUG "RUNNING DO_CLEAR",10,13
@ INT_CLEAR RBC_INT
PAUSE 250
GOTO HOLD_HERE

END

Here is the Circuit:


There are 4 buttons connected to PORT B <4.7>
Here are my observations:

The first press of any button activates the RBC Interrupt and sends program to DO_RBC_INT subroutine, then on to MENU where it checks for button presses. This behaves exactly as I would expect it to.

Now...After that....

Pressing Button RB.4 [ENABLE] Runs the DO_ENABLE subroutine then the HOLD_HERE subroutine. At this point, the Interrupt handler seems to shut down as no Port B inputs activate the interrupt handler. I would expect the Interrupt to remain active.

Pressing Button RB.5 [DISABLE] Runs the DO_DISABLE subroutine then the HOLD_HERE subroutine. The Interrupt handler is now disabled as expected.

Pressing Button RB.6 [RETURN] Runs the DO_RETURN subroutine then the HOLD_HERE subroutine. It then sends program to DO_RBC_INT subroutine, then on to MENU. I would expect it to return to HOLD_HERE which is wherr the interrupt was originally activated

Pressing Button RB.7 [CLEAR] Runs the DO_CLEAR subroutine. At this point, the Interrupt handler seems to shut down as no Port B inputs activate the interrupt handler. I would expect this to just clear the interrupt then await another RBC trigger.

So it seems I can only activate the interrupt one time.

It doesn't seem to matter whether I use ASM or PBP types or set Resetflag to yes, or no

Can anyone shed light on what I'm doing wrong, or am I simply misinterpreting the function of the INT_* utilities.

I'm just not sure if I've got a mistake, am staying up too late working on this stuff, or just really don't get it.

Thanks,
Bob