ON INTERRUPT questions

[Acetronics2]

I hate to sound dumb, but...

It has been a long time since I wrote ASM code for PICs.


My code is basically as below-

TOP:
IF TMR0 rollover then gosub TASK_SCHEDULER
IF PIR1.5 = 1 then gosub INPUT_ROUTINE
GOTO TOP

TASK_SCHEDULER:
(normally calls a bunch of very short routines - 300uSec max)
but- every once in awhile calls OUTPUT_ROUTINE
RETURN


INPUT_ROUTINE:
HSERIN stuff
RETURN

OUTPUT_ROUTINE:
HSEROUT [...]
RETURN

---------------------------------------
Questions:
Do I just put the address of 'TOP' in the interrupt vector?

> If TOP: is the label of your interrupt stubb ... yes. but, think to disable the asm interrupts while being in your receive section ...
> BUT the receive section MUST end with a GOTO, and not a RETURN ( Return address is totally false, here !!! )

Is there a way to automatically do this in PBP -

> It would have already been done, I think !!!

> Question has to be asked to Melabs or Mel Labs ( !!! ) ... I'm just a poor lonesome engineer !!! at this time, answer for me is no ...

some way that I don't have to look at the listing and find out what the actual address of 'TOP' is, and manually write that to address 0x08 (something like INT_VECTOR = TOP)?

> I do not know if labels can work here ( bi-directionnal translation ??? hex to asm and asm to hex ... hum ...) ... it's to try. But remember : you can't add or kill program lines at this step ...

Do I have to save/restore any other registers (STATUS or W, for example?)

> It is not necessary, as you go back to a full section of PbP code ... and redo a full task. but you've lost what you were doing ... may be care has to be taken with READ and WRITE to be sure values are really saved or read .
I'd better kill interrupts in those sections ...


Alain

[Acetronics2]

I did just a little try ...16F84A, button on PortB.0, Led on PortB.7

see :

'Test Blink

ON INTERRUPT GOTO Period
DISABLE INTERRUPT


DEFINE LCD_Ebit 1

I var Bit
Periode var Word

Led var Portb.7
Led = 0
Periode = 64


loop:

INTCON.4 = 1

For I = 1 to 1000
Pauseus Periode
Next I

Toggle led

Goto loop


Period:

INTCON = $80

Periode = ( Periode /2 )

IF NOT Periode THEN
Periode = 64
ENDIF


GOTO loop




END


the HEX, now, in the Program Window

Change line 5 ( RETURN ) to ( GOTO 0x54 ) ....

ENJOY !!!

That's all !!!

[Charles Linquis]

Thanks! I'll try it.

[Charles Linquis]

I'm using Microcode Studio, so I'm not familiar with Microchip's IDE.

I'm trying to figure out how you changed the return address of the interrupt routine to the address of my label ''CharInput'.

A couple of questions then:

Within the ASM file, how do I find out what address the various labels are located? My character input routine is call 'CharInput'. That is where I want the program to jump when it gets an interrupt from the serial port.

In the following, I see no RETFIE or RETURN where I could substitute the address of CharInput. Where do I find that?




Here is a portion of my ASM file.

; C:\PIC\BASIC\BAE5_INT.BAS 00175 ON INTERRUPT GOTO CharInput
ONINT?LL _CharInput, L00001

; C:\PIC\BASIC\BAE5_INT.BAS 00176 DISABLE INTERRUPT
IDISABLE?

[Acetronics2]

Hi Charles

Try this :

'Test Blink


DEFINE INTHAND _Period

I var Word
Periode var Word

Led var Portb.7
Led = 0
Periode = 64


loop:

INTCON = %10010000

For I = 1 to 1000
Pauseus Periode
Next I

Toggle led


Goto loop


Period:

INTCON = $80

Periode = ( Periode /2 )

IF NOT Periode THEN
Periode = 64
ENDIF


GOTO loop


END


!!! IMPORTANT NOTE !!! : DO NOT FORGET the underscore before Period , in the inthand DEFINE !!!

No mod to add to the Hex, this time !!!

No Retfie or Return to care with ... just give the jump label you want to go aft the interrupt stubb.

ENJOY

Alain

PS : Doesn't hurt MCS nor ....

[Charles Linquis]

Thank you, Thank you, Thank you!

I have modified my code to deal with a serial port interrupt, and (so far at least) it is working perfectly.