Thanks for the reply, John.

I'm not sure where you found that PDF, and I've been googling for a while
but can't find anything about a PIC24F with Chapter 10 being EEPROM. It's
always Chapter 5. **shrug**

But I still have a couple questions:
1) How do I know what the offset is supposed to be? The MPLAB X EEPROM tab
shows the EEPROM starting at address 0x7ffe00
2) I tried using your code, and also the code straight from the
PIC24F32KA301 data sheet. Still nothing, I can't get past the first hump of
writing data, let alone reading data.

Am I missing something extremely obvious?

This is driving me nuts!


int __attribute__ ((space(eedata))) eeData =3D 0x1234;
//Also tried:
//int __attribute__ ((space(eedata))) eeData[] =3D { 2, -1, -1, -1 };

void eeprom_write(int newData, uint offset) {
    NVMCON =3D 0x4004;                        //Set up NVMCON to erase one
word of data EEPROM

    //Set up a pointer to the EEPROM location to be erased
    TBLPAG =3D __builtin_tblpage(&eeData);    //Initialize EE Data page
pointer
//Also tried without the "&" pointer deref
    offset =3D __builtin_tbloffset(&eeData);  //Initizlize lower word of
address
//Also tried without the "&" pointer deref
    __builtin_tblwtl(offset, newData);      //Write EEPROM data to write
latch

    asm volatile ("disi #5");               //Disable Interrupts For 5
Instructions
    __builtin_write_NVM();                  //Issue Unlock Sequence & Start
Write Cycle
    NVMCONbits.WREN =3D 1;       //Also tried without this line
    //This seems to stall the PIC indefinitely, so I just comment it out
and __delay_ms(1) afterwards
    //while(NVMCONbits.WR =3D 1);               //Optional: Poll WR bit to
wait for
                                            //write sequence to complete
}

int eeprom_read(uint offset) {
    int data;
    // Set up a pointer to the EEPROM location to be erased
    TBLPAG =3D __builtin_tblpage(&eeData);    //Initialize EE Data page
pointer
    offset =3D __builtin_tbloffset(&eeData);  //Initizlize lower word of
address
    data =3D __builtin_tblrdl(offset);        //Write EEPROM data to write
latch
    return(data);
}

void main(void) {
    int j =3D 0;
    int z =3D 0;
    for(j =3D 0; j < 10; j +=3D 2) {
        z =3D ((j + 64) << 8) + (j + 64);
        eeprom_write(z, j + 0x7ffe00);
//Also tried:
//eeprom_write(z, j);
        __delay_ms(1);
    }
}




On Thu, Apr 30, 2015 at 7:36 PM, John J. McDonough <mcd@is-sixsigma.com>
wrote:

> On Thu, 2015-04-30 at 17:34 -0600, Mitch wrote:
> > I'm looking for a way to write data to non-volitile memory. It seems,
> even
> > though they say you can write EEPROM, everyone say to do EEPROM emulati=
on
> > with Flash.
> >
> > All the examples I've found for 24F for some reason does not work.
> > I've tried these:
> >
> http://www.ece.msstate.edu/courses/ece3724/main_pic24/docs/_p_i_c24_suppo=
rt.html
> > http://www.microchip.com/forums/m707241.aspx
> > http://www.microchip.com/wwwAppNotes/AppNotes.aspx?appnote=3Den530593
> >
> > The AN1095 PDF is quite a bit over my head and doesn't show any example=
s.
> >
> > Does anyone know of a library that would work for all 24F chips? Or
> should
> > I just stick with an external chip?
> >
> > Writing EEPROM was SOOOO easy with PIC16!!!
>
> Well, once you figured it out it was!
>
> I found the examples in the FRM to work.  It did seem to me that the
> data to write had to be global.  I saw no reason to require that, but it
> didn't seem to work without it.  My testing was on the KM2, but it looks
> to me that the KA3 is identical save a few peripherals.
>
> Maybe you'll inspire me to try it with the KA3 and finish the chapter.
>
> --McD
>
>
>
>
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