Instant Interrupts - Revisited

[Darrel Taylor]

Saves them all, no matter what.

Without an external program like VBIS for Proton, there's no way to know which system variables are being used by a particular Handler.

But from what I've seen, while optimizing out what isn't used does increase the maximum interrupt frequency available, it only really helps if you're pushing the limits. For normal everyday interrupts (with Basic Language) the extra saves don't have that much effect, and helps provide stability.

And as always, if you really need the speed ?
The interrupts should be in ASM anyways. (no PBP system variables saved at all)

Which is one of the best parts of DT_INTs.
You can have both ASM and Basic Language interrupts in the same program.
<br>

[mister_e]

And all this with a minimum of efforts

[Pic_User]

For the record (partial pasted from other thread):

Hi all, I've been trying to get Darrel Taylor's Instant interrupts to work with a 12f675 with no luck. Will they work with a 12f675?

I just get the following error message when I try to compile it:

ERROR: Variable wsave3 position request 416 beyond RAM_END 95.
ERROR: Variable wsave2 position request 288 beyond RAM_END 95.
ERROR: Variable wsave1 position request 160 beyond RAM_END 95.
ERROR: Unable to fit variable RS2_Save
<..snip...>
Thanks for any help.

Bill

See Darrel’s solution:
“To get Instant interrupts with Basic Language working on a 12F675 ...”
Open the DT_INTS-14.bas file and comment out the wsave lines. The 675 doesn't have any usable RAM in banks 1,2 or 3

' --- IF any of these three lines cause an error ?? ---------------------------- 
'       Comment them out to fix the problem ----
' -- It depends on which Chip you are using, as to which variables are needed --
;wsave1      var byte    $A0     SYSTEM      ' location for W if in bank1
;wsave2      var byte    $120    SYSTEM      ' location for W if in bank2
;wsave3      var byte    $1A0    SYSTEM      ' location for W if in bank3
' ------------------------------------------------------------------------------

Then in the ReEnterPBP.bas file comment the T?_save variables.

;    T1_Save     VAR WORD
;    T2_Save     VAR WORD
;    T3_Save     VAR WORD
;    T4_Save     VAR WORD

Just remember that if you use Instant Interrupts on a different chip later, you will need to un-comment those lines.
HTH,
__________________
DT
http://www.picbasic.co.uk/forum/show...9510#post49510

[debutpic]

Hello all

Today I play with " Instant Interrupts" thank's Darrel

For to begin I use blinky program
I want to augment the speed of blink light by loading a value
in TMR1H and TMR1L but the speed does not change

Rq:
I want not to change the value of the prescaler


code:

'********************
TMR1H = %11111111
TMR1L = %11111110
'********************

1CON = %110001 ; Prescaler = 8, TMR1ON

what is wrong please?

[Darrel Taylor]

I want to augment the speed of blink light by loading a value
in TMR1H and TMR1L but the speed does not change

code:

'********************
TMR1H = %11111111
TMR1L = %11111110
'********************

Loading that value %1111111111111110 = $FFFE = 65534
Means the timer will overflow after only 2 ticks.
A smaller number would help.

Also, it has to be loaded after every interrupt, not just at the beginning of the program.
<br>

[debutpic]

thank's Darrel

Remark:

In my next code if I load TMR1H with a high value code work fine

Main:

TMR1H = %11111111
pause 1

----------------------------

but if I reduce the value in TMR1H code don't work
display is OFF

Main:

TMR1H = %10111111
pause 1

-------------------------------
if I want use this value "TMR1H = %10111111"
I must write "pause 20" and not "pause 1"

an idea ???????

[Darrel Taylor]

No, I have no idea what you are doing.
If you're using a timer, why do you need pauses?

What frequency are you trying to run the timer at?
What frequency is your primary oscillator?
What PIC are you using?
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