Post by thread:Help EEPROM

Francesco Cembrola wrote: > > Hello PIC'ers, > > I need some help. Despite my best efforts, I have not been able to write to > the EEPROM of the PIC16C84. What I really would like is a written program of > how this is done. > > Please could anyone show me how to do this? It is hard when you are a novice! > > Thank you all, > > Francesco Cembrola > .....fcembrolaKILLspam@spam@aol.com Display this reply full screen for proper formatting. Are you sure you are not writing? but maybe reading wrong?Do you include eeprom data in your program listing? are you switching bank bits like you are supposed to ? Clip a relative piece of code for us to look at.Are you writing sequential bytes or just one? I read: BCF STATUS,RPO ; shift to bank zero MOVLW D'5' ; register eeprom addres s for ONES_BATCH MOVWF EEADR ; load address of eedata needed BSF STATUS,RPO ; shift to bank one BSF EECON,RD ; eeread bit set BCF STATUS,RPO ; shift to bank zero MOVF EEDATA,W ; eedata in w register MOVWF ONES_BATCH ; preset the register fr om eeprom value I write : INCF ONES_BATCH,F ; increment the ones_bat ch register BSF STATUS,RPO ; shift to bank one BSF EECON,WREN ; write enable bit BCF STATUS,RPO ; shift to bank zero MOVLW D'5' ; address of BATCH eepro m byte MOVWF EEADR ; address register eepro m MOVF ONES_BATCH,W ; load value of ONES_BAT CH variable to EEPROM MOVWF EEDATA ; BSF STATUS,RPO ; bank 1 MOVLW H'55' ; write 55h MOVWF EECON2 ; "" MOVLW H'AA' ; write aah MOVWF EECON2 ; "" BSF EECON,WR ; set WR bit begin write CLEARED IN HDW BCF EECON,WREN ; DISABLE EEPROM WRITES BCF STATUS,RPO ; shift to bank zero Some of this can no doubt be eliminated if the states on entry are known but this as a call from anywhere routine works ok.