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Discussion Groups | M68HC11 | IRQ on adapt11
Technical discussions about Freescale Microcontrollers: M68HC11. (Freescale Semiconductor is a Subsidiary of Motorola).
IRQ on adapt11 - fidjouss - Mar 21 14:40:00 2005
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Hello I wrote a small program to test the IRQ interrupt. i am using edge sensitive. Everytime i turn the switch off, I get something weird. and my 7 seg led turns off. can anyone please take alook at my program and see what s wrong. DIGIT0 EQU $00 PORTC EQU $03 PORTB EQU $04 DDRC EQU $07 PORTD EQU $08 DDRD EQU $09 REGBAS EQU $1000 ****************************************************** ORG $FE00 CONFIGURE: LDX #REGBAS BSET $39,X $20 LDS #$FF LDAA #$01 STAA DDRD,X ;PIN1 FOR OUTPUT LDAA #$00 STAA DDRC,X ;PORTC FOR INPUT CLR DIGIT0 CLI **************************************** HERENOW BRA HERENOW **************************************** READ_PORTC: LDAA PORTC,X STAA $00,X JSR DISPLAY CLI RTI **************************************** DISPLAY: LDAA $01 STAA PORTD,X ;TURN THE COMMON ANODE OF THE 7SEGMENTS ON LDAA DIGIT0 STAA PORTB,X ;OUTPUT TO 7SEG LED RTS ***************************************** ORG $FFF2 FDB READ_PORTC ORG $FFFE FDB CONFIGURE |
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Re: IRQ on adapt11 - Scott Grodevant - Mar 21 14:59:00 2005
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Hi all, The CLI in the interrupt handler isn't needed (and shouldn't be there). RTI restores the interrupt flag state. Be re-enabling interrupts inside the handler, you allow the potential for recursive entries (and might be overflowing your stack). In general, it's bad form not to save/restore all registers used and to assume any values (like X being set to REGBAS). Further, anytime you have magic numbers in your code, you (or someone else) will hate yourself later. On the other hand, given the context of the program, there is nothing wrong with what you've written. In DISPLAY, did you mean LDAA #1 to set B1 high? Good luck, Scott fidjouss <> wrote: Hello I wrote a small program to test the IRQ interrupt. i am using edge sensitive. Everytime i turn the switch off, I get something weird. and my 7 seg led turns off. can anyone please take alook at my program and see what s wrong. DIGIT0 EQU $00 PORTC EQU $03 PORTB EQU $04 DDRC EQU $07 PORTD EQU $08 DDRD EQU $09 REGBAS EQU $1000 ****************************************************** ORG $FE00 CONFIGURE: LDX #REGBAS BSET $39,X $20 LDS #$FF LDAA #$01 STAA DDRD,X ;PIN1 FOR OUTPUT LDAA #$00 STAA DDRC,X ;PORTC FOR INPUT CLR DIGIT0 CLI **************************************** HERENOW BRA HERENOW **************************************** READ_PORTC: LDAA PORTC,X STAA $00,X JSR DISPLAY CLI RTI **************************************** DISPLAY: LDAA $01 STAA PORTD,X ;TURN THE COMMON ANODE OF THE 7SEGMENTS ON LDAA DIGIT0 STAA PORTB,X ;OUTPUT TO 7SEG LED RTS ***************************************** ORG $FFF2 FDB READ_PORTC ORG $FFFE FDB CONFIGURE Yahoo! Groups SponsorADVERTISEMENT --------------------------------- Yahoo! Groups Links To --------------------------------- |
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Re: IRQ on adapt11 - fidjouss - Mar 21 16:00:00 2005
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Thanks for ur response. Yes I did mean #$01 for pin0 in portd. My question is when I simulate this program with thrsim11 (with a switch attached to irq) works fine and gives me correct results. However, the problem is when I transfer it to the adapt11. I think there is a problem in reading portc. whatever dip switch combinations I use, my 7seg led always displays the samething (all segments are on) when I put irq low. ( I am using a breadboard and when I want to mkae irq low i just plug attach a cable to the ground since I dont have a threway switch) Thanks --- In , Scott Grodevant <scott14468@y...> wrote: > Hi all, > > The CLI in the interrupt handler isn't needed (and shouldn't be there). RTI restores the interrupt flag state. Be re-enabling interrupts inside the handler, you allow the potential for recursive entries (and might be overflowing your stack). > > In general, it's bad form not to save/restore all registers used and to assume any values (like X being set to REGBAS). Further, anytime you have magic numbers in your code, you (or someone else) will hate yourself later. On the other hand, given the context of the program, there is nothing wrong with what you've written. > > In DISPLAY, did you mean LDAA #1 to set B1 high? > > Good luck, > > Scott > fidjouss <fidjouss@y...> wrote: > > Hello > > I wrote a small program to test the IRQ interrupt. i am using edge > sensitive. Everytime i turn the switch off, I get something weird. and > my 7 seg led turns off. can anyone please take alook at my program > and see what s wrong. > > DIGIT0 EQU $00 > PORTC EQU $03 > PORTB EQU $04 > DDRC EQU $07 > PORTD EQU $08 > DDRD EQU $09 > REGBAS EQU $1000 > ****************************************************** > ORG $FE00 > CONFIGURE: > LDX #REGBAS > BSET $39,X $20 > LDS #$FF > LDAA #$01 > STAA DDRD,X ;PIN1 FOR OUTPUT > LDAA #$00 > STAA DDRC,X ;PORTC FOR INPUT > CLR DIGIT0 > CLI > **************************************** > HERENOW BRA HERENOW > **************************************** > READ_PORTC: > LDAA PORTC,X > STAA $00,X > JSR DISPLAY > CLI > RTI > > **************************************** > DISPLAY: > LDAA $01 > STAA PORTD,X ;TURN THE COMMON ANODE OF THE 7SEGMENTS ON > LDAA DIGIT0 > STAA PORTB,X ;OUTPUT TO 7SEG LED > RTS > ***************************************** > ORG $FFF2 > FDB READ_PORTC > ORG $FFFE > FDB CONFIGURE > > Yahoo! Groups SponsorADVERTISEMENT > --------------------------------- > Yahoo! Groups Links > > To > > --------------------------------- |
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Re: Re: IRQ on adapt11 - Scott Grodevant - Mar 21 17:16:00 2005
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Hi all, I don't see the value in DIGIT0 being changed, it looks like it is always zero to me. I assume that means all LED segments would light. You read port C and save it in 0,X (very poor form), what memory location is this? Yeah, I don't know either. With my crystal ball in place, didn't you mean to read port C and save it in DIGIT0? Scott fidjouss <> wrote: Thanks for ur response. Yes I did mean #$01 for pin0 in portd. My question is when I simulate this program with thrsim11 (with a switch attached to irq) works fine and gives me correct results. However, the problem is when I transfer it to the adapt11. I think there is a problem in reading portc. whatever dip switch combinations I use, my 7seg led always displays the samething (all segments are on) when I put irq low. ( I am using a breadboard and when I want to mkae irq low i just plug attach a cable to the ground since I dont have a threway switch) Thanks --- In , Scott Grodevant <scott14468@y...> wrote: > Hi all, > > The CLI in the interrupt handler isn't needed (and shouldn't be there). RTI restores the interrupt flag state. Be re-enabling interrupts inside the handler, you allow the potential for recursive entries (and might be overflowing your stack). > > In general, it's bad form not to save/restore all registers used and to assume any values (like X being set to REGBAS). Further, anytime you have magic numbers in your code, you (or someone else) will hate yourself later. On the other hand, given the context of the program, there is nothing wrong with what you've written. > > In DISPLAY, did you mean LDAA #1 to set B1 high? > > Good luck, > > Scott > fidjouss <fidjouss@y...> wrote: > > Hello > > I wrote a small program to test the IRQ interrupt. i am using edge > sensitive. Everytime i turn the switch off, I get something weird. and > my 7 seg led turns off. can anyone please take alook at my program > and see what s wrong. > > DIGIT0 EQU $00 > PORTC EQU $03 > PORTB EQU $04 > DDRC EQU $07 > PORTD EQU $08 > DDRD EQU $09 > REGBAS EQU $1000 > ****************************************************** > ORG $FE00 > CONFIGURE: > LDX #REGBAS > BSET $39,X $20 > LDS #$FF > LDAA #$01 > STAA DDRD,X ;PIN1 FOR OUTPUT > LDAA #$00 > STAA DDRC,X ;PORTC FOR INPUT > CLR DIGIT0 > CLI > **************************************** > HERENOW BRA HERENOW > **************************************** > READ_PORTC: > LDAA PORTC,X > STAA $00,X > JSR DISPLAY > CLI > RTI > > **************************************** > DISPLAY: > LDAA $01 > STAA PORTD,X ;TURN THE COMMON ANODE OF THE 7SEGMENTS ON > LDAA DIGIT0 > STAA PORTB,X ;OUTPUT TO 7SEG LED > RTS > ***************************************** > ORG $FFF2 > FDB READ_PORTC > ORG $FFFE > FDB CONFIGURE > > Yahoo! Groups SponsorADVERTISEMENT > --------------------------------- > Yahoo! Groups Links > > To > > --------------------------------- Yahoo! Groups SponsorADVERTISEMENT --------------------------------- Yahoo! Groups Links To --------------------------------- |
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Re: IRQ on adapt11 - Paul B. Webster VK2BZC - Mar 21 17:29:00 2005
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On Mon, 2005-03-21 at 18:40 +0000, fidjouss wrote: > I wrote a small program to test the IRQ interrupt. i am using edge > sensitive. Everytime i turn the switch off, I get something weird. My hackles rise when you use the words "switch" and "IRQ" in the same sentence. May I presume that your "switch" is a construction on a "development" board consisting of a toggle switch or pushbutton whose output is processed by a debounce circuit, either a flip-flop whose inputs are controlled by the alternate contacts of the switch, or a schmitt-trigger gate with a 50 mS (or so) time constant feeding it? There may be exceptions, but interrupt inputs are *not* (suitable) for the purpose of detecting switch operation - you use "polling" of a switch connected to a general-purpose input (and debounce algorithms). You will note that for the exceptional case of waking from power-down mode, microprocessors (designed for this purpose) provide a particular mechanism for activating this function through a nominated input port (such as for example, mobile phones) which would be connected to the keypad, rather than IRQ. -- Cheers, Paul B. |
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