Using largish structures

[JDBoyd]

I'm having some trouble with using an array, which sounds really stupid. I ran into a similar problem earlier, but I just rearranged things until it started working correctly. Then 2 weeks later, I make a small seemingly unrelated change, and bam the problem is back, so I decided to cut the code out into an example program, that reproduces what I'm trying to do and the results I get.

I actually have two different examples here. Both examples use 128 bytes. One just uses a 128 byte array.
My data is 4 levels, 32 entries per level, and each entry takes 7 bits plus a dirty bit, so the other example uses structs and arrays. Both have trouble. If I read an element immediately after writing it, I get what I wrote, but if I read it later from a different function (say I read it correctly in the setter, but I read it incorrectly from 2 lines later in the function that called the setter) I get something different. There are no interrupts. The platform is a PIC18F46J50, so a few K of RAM. I'm using CCS PCH 4.110, 53371. I'm compiling from inside MPLAB version 8.53.

I include the two different methods since I've tried them both and they both misbehave. I'm hoping there is something obvious about PICs or CCS that I just don't know about. I also hope I'm not providing so much info that no one bothers reading the long post.

I've attached 4 files. Here are my structures and the code that reads/writes from them:

[PCM programmer]

Can you post a much smaller test program ? For example, all of the
following code can be cut. It sets up peripheral modules. It doesn't
have anything to do with structure problems:

[Wayne_]

One problem I see is that you are using the same name for both the output struct tag and a parameter in your function:-

[Ttelmah]

Another problem is declaring variables inside the code.
In C, variables must be declared at the _start_ of a code section. You technically can declare them inside a subsection (bracketted), but it is not legitimate to declare them 'mid code'. The compiler ought to complain about this, but since it doesn't, I'd suspect these are incorrectly being allocated to the same memory areas as earlier declarations, and hence values are being overwritten....

Best Wishes

[FvM]

There are two issues with your code:
1. You confused the argument order with dls_set2(). The function definition expected in your code is:

[JDBoyd]

PCM, I will continue to try to create a short example. Generally, short examples don't want to exhibit the same behavior as the larger program.

To everyone else, I will go through and apply the suggestions about not using C99 style variable definitions in the middle of a block, and not mixing variable declaration with value assignment, as well as making sure that type names and variable names never overlap (although, it seems rather crummy if PCH can't handle that).

You are correct about the mixed up argument order, but that was not the case in the main project's code, only in the test program.

[FvM]