PIC16F18857 No access to EEPROM, failure on all sides

[renew]

Hi, people. I am using PIC16F18857 this time and as usual I triedto use the built-in EEPROM library which is very easy

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int a;
a = 5;
EEPROM_Write(0x0000, a);
a = EEPROM_Read(0x0000);

But it does not work, the reading result is always 0.

I wrote my own lib

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char EEPROM_Read(char a){
   NVMREGS_bit = 1; // to eeprom
   NVMADRH = 0xF0;
   NVMADRL = a;
   NVMCON1.B0 = 1; // RD = 1
   while(NVMCON1.B0){asm NOP;}
   return NVMDATL;
}

But it does not work too, result is always 0, it should be 255 from freshly erased cells.

I have tried to use the built-in EEPROM Tool, to write first cell to some value, but output HEX causes error while import to Microchip IPE - "this file contanes data by outrange allowed address for PIC16F18857".

So I tried everithing what I could and dont know what to do next.

[janni]

That's due to error in definition file - follow instructions in this topic. The fix is for another processor but will work for yours as well.

[renew]

Hi. Thank you.
That fix allows me to use EEPROM Editor tool properly.
Now I can set needed cells by values.

But I still cant read and write cells with built-in library and with my reading function.

Actually the correct address is 0xF000

[janni]

Actually the correct address is 0xF000

Yes, but compiler automatically adds 0xF000 to EEPROM address parameters in .mlk file so the addresses there do not need the offset.

That fix allows me to use EEPROM Editor tool properly.
Now I can set needed cells by values.

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But I still cant read and write cells with built-in library and with my reading function.

Don't know why - your function looks fine (though there's no need to wait for the RD bit).

[renew]

I have found that

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NVMDATL = 1;
NVMDATH = 2;
Write_Integer(160, 6, NVMDATL + NVMDATH, 5);

Both registers are always zero regardless of what is was written in them before.

[renew]

From datasheet:

When read access is initiated on an address outside
the parameters listed in Table 10-3, the NVMDATH:
NVMDATL register pair is cleared, reading back ‘0’s.

[renew]

I am sorry !!!
NVM Module was disabled by PMD Control.
All works now