Issues with CCS C Compiler and Variable Initialization

moriro3436 · Joined: 06 Aug 2024 Posts: 2

Hello, everyone.

I am experiencing problems with variable initialization in the CCS C Compiler. When I execute my code on a PIC microcontroller, my variables do not appear to be initialized as planned. Specifically, I'm observing inconsistent behavior with global variables that should be changed to zero but appear to keep their former values.

Here is the code:

temtronic · Posted: Mon Aug 26, 2024 5:14 am

try this method...

int globalVar=0;

..and see what happens.

It could be a compiler bug. Always post your compiler version , as well as which PIC. Post a small program that shows the problem. That way others can cut/paste/compile/test your code.

Ttelmah · Joined: 11 Mar 2010 Posts: 19496

A global variable is not initialised unless you say to do so.
A _static_ variable should be initialised to 0.
As Jay says if you want it to initialise, you have to specify this.

This is deliberate, since this is what allows you to have the variable
contents maintained after a watchdog restart. If you want them to be
zeroed, you simply add #ZERO_RAM

You don't explain what you have not found the solution to?.
The point in that thread, was that the functions being asked for (play
etc.), are _not_ keyboard functions, and there is no defined keyboard
scancode for these. These are multimedia controller codes, and you have
to program the device to implement two USB devices. A keyboard, and
a multimedia controller, to then allow this type of function to be
implemented.
A keyboard' cannot send these codes.

If the variable is non zero after you explicitly clear it, then you have a
code problem, Look at the symbol table. What variable is immediately
in front of this one?. What variable immediately after?. Do you use
pointers anywhere?. The common reason for a variable being corrupted,
is an overrun by another variable or pointer.