Hi,

I'm having a wierd problem writing/reading to the EEPROM on the f877. I wanted
to make two routines to write and read, and this is what I came up with:

;Writes the value in W to the address in 'temp'
EEPROMWrite

 bsf STATUS,RP1   ;Switch to bank 2
 movwf EEDATA
 bcf STATUS,RP1   ;Back to Bank 0
 movf temp,w
 bsf STATUS,RP1   ;And back again to Bank2
 movwf EEADR

 ;Set to Bank 3
 bsf STATUS,RP0
 ;Enable EEPROM Writing
 bsf EECON1,WREN

 movlw 0x55
 movwf EECON2
 movlw 0xAA
 movwf EECON2
 ;Begin Write
 bsf EECON1,WR
 bcf EECON1,WREN

 ;Switch back to Bank 0

 bcf STATUS,RP0
 bcf STATUS,RP1

retlw 0x00

;Reads the value at address W and puts it back in temp
EEPROMRead

 ;Switch to bank 2
 bsf STATUS,RP1
 ;Move the address in W to EEADR
 movwf EEADR
 ;Switch to bank 3
 bsf STATUS,RP0
 ;Start the reading
 bsf EECON1, RD
 ;Back to Bank 2
 bcf STATUS,RP0
 movf EEDATA,w

 ;Switch bank to Bank 0
 bcf STATUS,RP1
 bcf STATUS,RP0
 ;Move the contents of W to temp
 movwf temp

retlw 0x00

Now what's wierd is that I called the Write fn twice, two different values,
different addresses... and then called read on one of them. I read it fine...
I then rewrote the code to read the other address (just one at atime), and I
got the same thing?? So I'm not sure which fn. is working incorrectly.

Anything seem to be wrong with my code? I know it's probably a bit
inefficient, but I just want to get it working first. If you guys do'nt see
anything wrong with this, I will look a bit closer at my fn to display the
numbers on my LCd, but I'm pretty sure that's not the problem since it works
for everything else.

Thanx,

Jai




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