Antonio L Benci wrote:
>
> I am trying, so far in vain, to write some code for a 12C509 device
> which has to do the following (shown in pseudo C code):
>
>         Power on Device Reset;
>
> main{
>     TRISB(0b11111100);
>     CLEAR GPWU; CLEAR GPPU;
>
>     switch (RESET_CAUSE()) {
>             case NORMAL_POWER_UP:   GP0=0, GP1-1;
>             case MCLR_FROM_SLEEP:   GP0=1, GP1-0;
>             case default:           error_handle();
>             }

Your switch statement is always going to fall through to the default
error_handle function.

You need a "break" statement in each of the case levels:

 switch (RESET_CAUSE())
    {
    case NORMAL_POWER_UP:
        GP0=0, GP1-1;
        break;
    case MCLR_FROM_SLEEP:
        GP0=1, GP1-0;
        break;
    case default:
        error_handle();
        break;
    }

The last break is not necessary but, unless you're really tight on code
space, it's good to put it in for clarity.

--Matt