Array

[lord loh.]

Can anyone help me give a clue on how to implement arrays in assembly (PIC18F452) ?

I would like to address a sequence of bytes...

Please help.

 

[Nigel Goodwin]

Can anyone help me give a clue on how to implement arrays in assembly (PIC18F452) ?

I would like to address a sequence of bytes...

Please help.

Here's a clue - "indexed addressing".

 

[lord loh.]

Here's a clue - "indexed addressing".

Okay... I searched through the datasheet, the keyword was "Indirect Addressing"...I was looking for instructions like those in 8085....

Is it possible to use arrays in Assembler variables? The help file does not say anything about it...

 

[Nigel Goodwin]

Okay... I searched through the datasheet, the keyword was "Indirect Addressing"...I was looking for instructions like those in 8085....

Sorry just working from memory!.

Is it possible to use arrays in Assembler variables? The help file does not say anything about it...

There's really no such thing as an 'array', it's just how you deal with a section of memory, normally RAM, but in a PIC GPR's. I don't think there's any such thing as an 'assembler variable', as far as programming goes, it's just a variable the assembler can use, and has no relation to the PIC at all.

Just allocate a sequential block of GPR's and use indirect addressing from the start address.

 

[lord loh.]

Oh no.... I was familiar with the 8085. So I was looking for some instructions like MOV M and INX H and STAX type... It did not occur to me to look for Indirect Addressing.

And I wanted to make an array of variables that are defined by SET or Variable assembler directives..

 

[Nigel Goodwin]

And I wanted to make an array of variables that are defined by SET or Variable assembler directives..

As far as I'm aware, those are only assembler directives - they don't produce any code at all, and have nothing to do with actual PIC code. Generally assembler variables are used to produce code for different processors based on a variable for the processor type, or for different clock speeds - but in each case you have to write each section of code, the assembler variable just allows you to select a particular section of code at assembly time, based on the value of the variable.

It's a common mistake to assume they produce PIC code, I get many emails from people doing just that - my usual response is to get them to look at the resulting code, and there isn't any!.

 

[lord loh.]

I am aware that SET and Variable does not produce any code....

But I have a piece of code that can be iterated using indirect addressing but I need several literals that have been defined by SET and Variable directives...

So I was seeing if there was a way to include different literals during different iterations...