Trying to write on an EEPROM

[kyru27]

I'm asking for help to be able to write an EEPROM properly, I have checked that I can program it all 0's (that's sooo useful) but I get an error wherever I try to input something different at the adress that is on:

I think the screenshoots help with this:

This happens wheter I insert the EEPROM on the socket of Pickit 2 clone or I connect it to my Pickit2 unit via ICSP wires (while doing this some other situations have also happened and after that they have disappeared, but I guess this is the nearest thing I have now to get it working so I'm starting with this).

It's not the EEPROM fault as this is the second one and I seriously doubt 2 of them are going to have the same problem.

I think it's problem of trying to program a "1" in it, as I believe the Pickit2 starts recording it and when it has a problem it displays the error (I mean it's not via software that it could not put a "1" in this adress whatever the reason), and the fact that it sucess on programming an all 0's EEPROM seems to support that. But no idea why this happens.

Does anyone have any idea?

Thanks.

 

[Ian Rogers]

If you are using pickit2.... you will still need a pullup resistor(4k7) on the SDA line.

 

[kyru27]

Doesn't work... Anyway, it's a 25LC, that, in fact, according to the PICkit2 readme shouldn't even need a pull-up:


Connections for 25LC devices
---------------------------------------
PICkit 2 Pin 25LC Device Pin (DIP)
(1) VPP 1 nCS
(2) Vdd 8 Vcc
(3) GND 4 Vss
(4) PGD 2 SO
(5) PGC 6 SCK
(6) AUX 5 SI
7 nHOLD - disabled (Vdd)
3 nWP - disabled (Vdd)

I've done the equivalence of SI being the same as SDA (as that was the same pin in the 24LC series), just in case it was needed and was a readme mistake.

I'm not too sure of the meaning of

7 nHOLD - disabled (Vdd)
3 nWP - disabled (Vdd)

Anyway I think I have tested all the posibilities that could mean, I mean, either not having it wired to anything or both wired to Vdd from Pickit2 (and in this last case it isn't able of even programming an all 0's EEPROM). But maybe it's something I'm still missing something about this.

Thanks for your help.

Edit: Seems to be some type of issue with the AUX signal, as I can do the same (programming all 0's) without it, the wire is approximately the same lenght as the others that work to program a PIC, and it seems to be working right as it's almost giving the same voltage at the pin 5 of the EEPROM than in the ICSP connector.

Does it maybe need some type of special configuration?