topic Re: Internal EEPROM Corruption in MC9S12XDP512 in S12 / MagniV Microcontrollers

Internal EEPROM Corruption in MC9S12XDP512

kp2309 — Thu, 18 Dec 2008 19:44:16 GMT

Hey guys

We are using MC9S12XDP512 controller for our existing product development.

The internal EEPROM of the controllers is getting corrupted permenantly in some cases.

It is not becoming default even after reprogramming the controller.

It works fine and we are able to read and write properly for some time.

We are using 190kHz frequency for EEPROM.

Also we are erasing the sectors before writing into EEPROM.

The product is in the last stage of release and suddenly we are facing such critical problem

Can anybody please tell me what are the areas which I should look in for finding the solution.

What can be the reasons for permenant corruption of EEPROM from hardware as well as software design point of view???

Please reply ASAP.

-Regards,

Re: Internal EEPROM Corruption in MC9S12XDP512

kef — Thu, 18 Dec 2008 21:22:26 GMT

Sounds like bad ECLKDIV setting. Please tell us

1) what are your crystal (or external clock frequency) and bus clock frequencies.

2) what's you code to set up ECLKDIV. If you don't want to show the code, then please read contents of ECLKDIV register after setup is done in normal mode (not using BDM).

Re: Internal EEPROM Corruption in MC9S12XDP512

kp2309 — Fri, 19 Dec 2008 14:38:55 GMT

Crystal frequency = 8MHz
We are using PLL to make it 40MHz hence Bus Clock = 20MHz
ECLKDIV = 0x2A
After calculation EECLK comes out to be 190kHz

Re: Internal EEPROM Corruption in MC9S12XDP512

kef — Fri, 19 Dec 2008 16:28:42 GMT

Setting is OK, but are you sure ECLKDIV is set up properly? So what's your code, or what do you read from ECLKDIV in normal mode? Look for what Lundin replied here

http://forums.freescale.com/freescale/board/message?board.id=16BITCOMM&message.id=2793&query.id=72910#M2793

Also, what did you mean by

It is not becoming default even after reprogramming the controller.

Does it mean EEPROM isn't erased during erase and reprogram over BDM? Well, if you didn't disable EEPROM erasure, then maybe EEPROM erase/program limit was reached and part is damaged?

Message Edited by kef on 2008-12-19 10:41 AM