View Full Version : 16F84A EEPROM Programming

- 7th March 2005, 14:09
Hi, Everybody

I Have a little problem with my 16F84A EEPROMs ...
I am working with PBP 2.45a,MPLAB 7.01 and Picstart+ Upgraded.

With a brand new chip no problems, Loading values to EEPROM Works pretty Well ...

But, with an already programmed chip, I need to reset All EEPROM values to $FF ... ( DATA $FF(64) at the end of the config. section of my program)

Here comes the problem ...
MPLAB tells everything all right, "verify" tells everything Ok ...

BUT, a "read" shows Old values are still here, and an "on board" run shows it too ...

Has anyone ever dealt with such problems ???

... I know it's not PBP's fault nor mine ...


- 7th March 2005, 16:44
In MPLAB, go to Configure>> Settings >>Program Loading and check Clear EE data upon loading a program

- 7th March 2005, 17:42
Thanks, steve

But it's already done ... ( also default setting, i think )

Even microchip tell me to erase device before re-programming...so, it's a real bug !!!

As their SSR 19753 says clearly EEPROM ERase doesn't work with 16F628, 16F84 and 16F876 ... what to do ?

Really Funny ... isn't it !!!


- 7th March 2005, 17:53
nop it's not a default setting.

I still don't understand why Microchip don't offer, like many other programmer software, this 'erase before programming' option... well MPLAB is free ;)

i was not aware of this SSR 19753... so i guess you must clear them manually directly in the View>> EEPROM , right click on the window and choose Fill memory

- 7th March 2005, 18:03
Sorry Steve ... doesn't work either !!!

All Other values ...except FF !!!


- 7th March 2005, 18:56
Oh my gooood!!!

fill memory with FF

uncheck auto select memory areas and range
check EEPROM data

program your PIC... read it back... you're now in business

- 8th March 2005, 06:14
Hi, Steve

Seems impossible to write FF ( or erase ) to the EEPROM ... I had tried this way too ... memory window just can show his red face !!! no more.

I think, I have to wait for the 7.02 Release ...

Have a nice day


- 8th March 2005, 17:40
Hi, Everybody

Here is the answer from Microchip :

You are correct, regarding SSR19753, even though the PIC16F84A is not mentioned. I have informed the development systems group about this.

The enhancement to erase EEPROM is planned for MPLAB IDE v7.20.

Issuing an Erase when the device has been code protected will clear the entire device of data. A Blank Check will state the device is blank
Programming the entire device with new data will change all memory areas. If for example this data were the reset values, a Blank Check after programming would reflect the device is blank.

So must we do ...

Good quiet night to you, folks ...