EEPROM writing, "unique" result - Electronic Circuits Projects Diagrams Free

ArtemisGoldfish · 29th January 2007, 03:29 AM

I'm just full of problems, aren't I?
Now, I've started programming in Assembly and WOW, it's a whole lot easier than I thought. As a test to make sure my PIC is functioning correctly, I wrote (stole most of the) code for writing to EEPROM. Since it's short, here it be:

#include <P16F876A.inc>

BSF STATUS,RP1
BSF STATUS,RP0
BTFSC EECON1,WR
GOTO $-1
BCF STATUS,RP0
MOVF 0x0000,W
MOVWF EEADR
MOVF 0x3F,W
MOVWF EEDATA
BSF STATUS,RP0
BCF EECON1,EEPGD
BSF EECON1,WREN
MOVLW 0x55
MOVWF EECON2
MOVLW 0xAA
MOVWF EECON2
BSF EECON1,WR
BCF EECON1,WREN

loop NOP
GOTO loop
end

Now, when I write it to my PIC (JDM programmer, IC-Prog 1.05D), hook it up, etc, and I plug it back into my programmer and read from it, the EEPROM location 0x0002 was written to instead of 0x0000, as I had copied to the EEADR register. Well, errr, What up with that?

Thanks again, community, for putting up with me.

Pommie · 29th January 2007, 04:55 AM

Your writing whatever is in SFR 3F into EEPROM at address, whatever is in SFR 00.

Try changing it to,

Code:

	BCF STATUS,RP0
	movlw	00;  < change
	MOVWF EEADR
	movlw	0x3f;< change
	MOVWF EEDATA
	BSF STATUS,RP0
	BCF EECON1,EEPGD

Try that and report back.

Mike.

ArtemisGoldfish · 29th January 2007, 11:24 PM

Quote:

Originally Posted by Pommie

Your writing whatever is in SFR 3F into EEPROM at address, whatever is in SFR 00.

Try changing it to,

Code:

	BCF STATUS,RP0
	movlw	00;  < change
	MOVWF EEADR
	movlw	0x3f;< change
	MOVWF EEDATA
	BSF STATUS,RP0
	BCF EECON1,EEPGD

Try that and report back.

Mike.

Hm, fancy that. Thanks, Mike. I'll try more fancy little configurations and say if I have any more problems that are EEPROM-based.

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29th January 2007, 03:29 AM	(permalink)
ArtemisGoldfish	EEPROM writing, "unique" result I'm just full of problems, aren't I? Now, I've started programming in Assembly and WOW, it's a whole lot easier than I thought. As a test to make sure my PIC is functioning correctly, I wrote (stole most of the) code for writing to EEPROM. Since it's short, here it be: #include <P16F876A.inc> BSF STATUS,RP1 BSF STATUS,RP0 BTFSC EECON1,WR GOTO $-1 BCF STATUS,RP0 MOVF 0x0000,W MOVWF EEADR MOVF 0x3F,W MOVWF EEDATA BSF STATUS,RP0 BCF EECON1,EEPGD BSF EECON1,WREN MOVLW 0x55 MOVWF EECON2 MOVLW 0xAA MOVWF EECON2 BSF EECON1,WR BCF EECON1,WREN loop NOP GOTO loop end Now, when I write it to my PIC (JDM programmer, IC-Prog 1.05D), hook it up, etc, and I plug it back into my programmer and read from it, the EEPROM location 0x0002 was written to instead of 0x0000, as I had copied to the EEADR register. Well, errr, What up with that? Thanks again, community, for putting up with me.

29th January 2007, 04:55 AM	(permalink)
Pommie	Your writing whatever is in SFR 3F into EEPROM at address, whatever is in SFR 00. Try changing it to, Code: BCF STATUS,RP0 movlw 00; < change MOVWF EEADR movlw 0x3f;< change MOVWF EEDATA BSF STATUS,RP0 BCF EECON1,EEPGD Try that and report back. Mike.