Instant Interrupts - Revisited

[Darrel Taylor]

You have to be using MPASM as the assembler.
The default PM assembler will not work.
<br>

[tenaja]

Darrel,
How about a little tutorial on how to tell which assembler is in use, and how to switch to the mpasm?

[Darrel Taylor]

OK, how bout this for detection ...

ASM
  ifdef PM_USED
       "Dude, you have to use MPASM with DT_INTS"
  endif
ENDASM

If you put that in your program, and try to assemble it with PM.exe, It will automatically pop-up a window in MicroCode Studio like this ...

<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=2450&stc=1&d=120694493 9" />

Then you can just click on "Compile Using MPASM", and it will set the MPASM option and compile it.

If it still fails to compile, you should try this ...
http://www.picbasic.co.uk/forum/show...5&postcount=11

I should add that to DT_INTS-14.

hth,
<br>

[sayzer]

Hi DT,

I wanted to post a "thank you" (also as an informative post).

For the first time ever, I used your 18F routine (with RX_INT) about a minute ago.

I saved 3100 bytes!!!

Really very interesting for me.

Thanks a lot for your amazing work.

[Darrel Taylor]

Hi sayzer,

2 years and 3 months since you joined.
What took you so long?

WOW! Saved 3100 bytes. That's pretty impressive.

Can I ask what the difference was? or maybe where the savings came from?
<br>

[sayzer]

Hi sayzer,

2 years and 3 months since you joined.
What took you so long?

WOW! Saved 3100 bytes. That's pretty impressive.

Can I ask what the difference was? or maybe where the savings came from?
<br>

The interesting part is that I did not change anything other the "int" part.

That is why it was surprising and "Really very interesting for me".

[Ioannis]

You mean that comparing to On-Interrupt of PBP you did a reduction of 3100?

Ioannis

[bcd]

I have been playing with the code shown below on a 16f737 as I was trying to get different prescaler values into the int routinues. As part of the testing I stripped the code right back to just be a simple interrupt with a value loaded into the pre-load registrer, but I seem to end up with an interrupt time of 204uS. According to the Timer Calc in Mister E's PicMulti Calc I should get an interrupt every 5.019mS. (see attached image for capture of the output waveform - I love my PICkit 2!)

This code is lifted straight from Darells example with the blinky led (1-2-3 version), and all I have done is add the pre-load. I have also removed the pre-load and still get the same time for the interrupt.

DEFINE OSC 20

rs_led      var portb.7 ' rs232 led
led         var portc.4 ' was Data_Out line

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

INCLUDE "DT_INTS-14.bas"     ' Base Interrupt System
INCLUDE "ReEnterPBP.bas"     ' Include if using PBP interrupts


ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
       INT_Handler   TMR0_INT,  _doBAM,   PBP,  yes
     endm
    INT_CREATE     ; Creates the interrupt processor
ENDASM

OPTION_REG = OPTION_REG & $80 | 1     'Set TMR0 Prescaler to 256, leave RBPU alone

TMR0 =  158 ' preload with 158 to give 21uS interrupts (at 1:1)
' this should then give Interrupt every 5.019mS at 1:256

@ INT_ENABLE  TMR0_INT     ; enable Timer 1 interrupts
'~~~~~~~~~~~~~~~~~~

goto main      ' jump over ISR

'---[TMR0 - interrupt handler]--------------------------------------------------
doBAM:
toggle rs_led
@ INT_RETURN

'~~~~~~~~~~~~~~~~~~~~~~~~~~~
 high rs_led
main:

'''''''''''''''''''''''
' do some flashing led stuff
'''''''''''''''''''''''
high led
pause 500
low led
pause 500
goto main

There has got to be something really simple I am missing...
bill.

[Darrel Taylor]

Use OPTION_REG = %11010111

And load the timer on every interrupt.
<br>

[bcd]

Thanks,

See told you it would be something really simple I missed..

doBAM:
   toggle rs_led
   TMR0 =  158     ' reload the pre-load
   @ INT_RETURN

(Hey Darrel - how do you get your code blocks so colourful and properly indented ?)

bill.

[skimask]

(Hey Darrel - how do you get your code blocks so colourful and properly indented ?)
bill.

http://www.picbasic.co.uk/forum/showthread.php?t=6221

The page may take awhile to load.....

[leisryan]

Hello;
I'm Ryan form the Philippines I must admit DTS-14 ints rules!!! i'd like to know how can i turn the interrupt on and off for USART continues recepton I'm using PIC16f877a toggling register PIE.5 doesn't seem to work

Thanks

PS.

Part of my project i'm paying my tuition continue college again OSY for sometime now hehe (",)