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Hi folks,

Can somebody please help me get a routine together that will allow me
to write a word sized variable to the memory of a 16f819 and be able
to read it back when the chip powers up. I know this is not rocket
science, but for whatever reason I cannot for the life of me figure it
out.

Thanks
Gary


(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

I believe that writing to EEPROM will do what you
want. Your chip has 256 bytes.

To WRITE:

WRITE 0,Variable.HighByte,Variable.Lowbyte

To READ:

READ 0,Variable.HighByte,Variable.Lowbyte

Charles Linquist

meriachee wrote:
>
> Hi folks,
>
> Can somebody please help me get a routine together that will allow me
> to write a word sized variable to the memory of a 16f819 and be able
> to read it back when the chip powers up. I know this is not rocket
> science, but for whatever reason I cannot for the life of me figure it
> out.
>
> Thanks
> Gary
>
>


(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

Here is some code I use in a 16F627A:

void writeEEPROMbyte(uns8 argAdr, uns8 argByt) {
GIE = 0; // disable interrupts - the
write seq requires a specific number of cycles or will fail

while (GIE) {
// make sure interrupts are disabled
}

EECON1.2 = 1; // set write enable flag WREN (EECON
bit 2)

EEADR = argAdr; // select eeprom address
EEDATA = argByt; // load data register byte

EECON2 = 0x55; // write sequence mystery #1
EECON2 = 0xAA; // write sequence mystery #2
EECON1.1 = 1; // set write trigger WR
(EECON bit 1)

while (EECON1.1) {
// wait for WR to be cleared by PIC
}

EECON1.2 = 0; // clear WREN
EEIF = 0; // clear EEIF

GIE = 1; // enable interrupts
}

void readEEPROM() {
EEADR = 0; // select eeprom address 0
EECON1.0 = 1; // set read enable flag RD
N_COL = EEDATA;

EEADR = 1; // select eeprom address 1
EECON1.0 = 1; // set read enable flag RD
N_LIN = EEDATA;
}

Hope this helps some.

--
Best regards,
Patrick Griffin
www.RedBinary.com

--- In p...@yahoogroups.com, "meriachee" wrote:
>
> Hi folks,
>
> Can somebody please help me get a routine together that will allow me
> to write a word sized variable to the memory of a 16f819 and be able
> to read it back when the chip powers up. I know this is not rocket
> science, but for whatever reason I cannot for the life of me figure
it
> out.
>
> Thanks
> Gary
>



(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )