Setting file registers with pointers

Hi all,

Does anybody have any low level ASM code to send/receive via SPI that will work on a 12F675 and that they are willing to share? That will solve my issue.

Otherwise, I'm writing my own...

I want to write a subroutine that saves 1, 2 .... x bytes into memory that it receives via SPI.

Is there any way on the mid-range MCUs to set a file register pointed to by another file register, for example something like:

movlw 022h ; Move 22h into W
movwf 021h ; Move W into file register 21h
movlw 0e6h ; Move e6h into W
movwf [021h] ; Move W into file register pointed to by 21h
.
.
.
inc 021h,1 ; Increment my pointer
goto writeloop ; Loop through

Obviously I won't look continuously incrementing forever. Just wanted to simplify the code above.

I don't think there is a way to do it, but hopefully somebody has some tricks.

Thanks,

David

Look at the FSR register.

Example,

Mike.

Got it, thanks so much

Does the indirect addressing with FSR/INDF work for reading registers as well as writing to registers?

Thanks,

David

Yobortsa said:

Got it, thanks so much

Does the indirect addressing with FSR/INDF work for reading registers as well as writing to registers?

Thanks,

David

Click to expand...

Yes... you use INDF like any other register, only instead of it being a fixed register, it reads or writes to whatever FSR is pointing at.

So... for example, let's copy the contents of 0x21 into 0x22 using indirect addressing...