ON INTERRUPT questions

[Ioannis]

Within your send routine, can you send character by character your string and check in between for the PIR1.5 ?

The delay would be one byte maximum.

Ioannis

[Charles Linquis]

I thought of that method myself last night, and have already started implementing it. That seems to be the best alternative right now.

I suppose that I need to check the listing file, but I need to make certain that I'm never "blind" for a significant part of a character reception period. I can't afford to miss even one character. There is no pacing. The data stream is coming from a computer, not a human.

I'm thinking that there should be some easy assembly language routine that - upon interrupt, just dumps me to a particular line and starts execution there. As I said before, I don't need to pick up right where I left off. If I'm sending a string, and a character comes in, I can stop sending data and respond to the new request.

[Ioannis]

I need to make certain that I'm never "blind" for a significant part of a character reception period. I can't afford to miss even one character.

You won't since you will be checking every one byte. The PIC buffer is 2 bytes long.

I'm thinking that there should be some easy assembly language routine that - upon interrupt, just dumps me to a particular line and starts execution there.

Either ASM or Basic the result with the suggested method will be the same. Maybe with ASM a few microseconds faster.

Ioannis

[Acetronics2]

I'm thinking that there should be some easy assembly language routine that - upon interrupt, just dumps me to a particular line and starts execution there. As I said before, I don't need to pick up right where I left off. If I'm sending a string, and a character comes in, I can stop sending data and respond to the new request.

Hi, PbP kings ... Mel and Co.

I see something interesting here ...

Just add :

ON INTERRUPT GOTO xxxy
DISABLE INTERRUPT

at the very top of the pbp program.

DO not Forget to end your interrupt routine xxxy: with a ( PbP ) GOTO where you want to go back then.


What's new in the asm Program window ???

program address 3 and 4 are now free, there's a new "return" at address 5 ... change it for a nop.

Label L 0001 ( a bit further ) contains the interrupt lines for PbP ... replace them by nops.

as there are no PbP lines between ON Interrupt and Disable ....There are no Gosub L0001 !!!

at address 3 put a GOTO 0006 to skip line 4 and 5

at address 4 ... just set the page bits ( if necessary ) and add an asm "GOTO" to the PBP interrupt label ( in address 4 or 5, Then)

we've seen 8 lines on 8 ...

I think it might work now ...

Alain

PS: example given for an interrupt vector at line 4 ... of course !!!

[Charles Linquis]

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?
Is there a way to automatically do this in PBP - 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)?
Do I have to save/restore any other registers (STATUS or W, for example?)

[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.