Faster SHIFTOUT without dedicated hardware, possible?

[tumbleweed]

You're right, for a PIC18 WREG is the name of a register.

If you're using a PIC16 then you have to declare a variable named WREG as I mentioned in post #9

If you're using a PIC16 then you'll have to add a definition for a WREG variable

WREG var byte

If you wanted to make the code the same for all devices then change all the references to WREG to a byte variable instead, including the SHOUT subroutine.
Here I've named it SHDATA.

SHDATA var byte

SHDATA = $55
call SHOUT

[CuriousOne]

It works fine without definition on PIC16F1828.
In fact, if I add definition, compiler gives an error - Redefiniton of VAR
This is why I asked

[tumbleweed]

If you're using an enhanced midrange PIC16 device (like the PIC16F1828) then it has a WREG, so it works with them too without having to declare a 'WREG' variable.

It's only for the older PIC16's you'd have to define it, or just change all the references to WREG to a new variable name of your choice.

[CuriousOne]

The above code works fine with TM1629A display.
But it does not work properly with APA102C leds.
I have the following statement:

SHIFTOUT di, ci, 1,[224+Bri[x],COLORS[X+16],COLORS[X+8],COLORS[X]]

Which I have replaced with

wreg=224+Bri[x]
gosub shout
wreg=COLORS[X+16]
gosub shout
wreg=COLORS[X+8]
gosub shout
wreg=COLORS[X]
gosub shout

The issue is that only odd bytes got transferred.
Say if I set some value to 2 or 4 it gets delivered to LEDs, but if I set it to 1 or 3 or 5 - nothing happens.
Tried to insert pause between each subroutine call - no difference

[CuriousOne]

I also tried to add some NOPs as suggested above - no difference.

[tumbleweed]

Don't know what to tell you... the routine transfers any values for WREG so there's no difference between odd/even values.

Must be some issue with the APA102C timing/format.

[CuriousOne]

I will hook up scope and check both "versions", to find the possible issue.