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Hello all, This is for all you software guru. Following is the problem: I suspect that I'm having some data corruption problem to my EEPROM (EE) and I would like to do a checksum to verify data integrity during write and read of the EE. I know how to do a checksum, but my problem is how I go about doing this. More specifically, where within my code (before read/write of EE) do I do the checksum. Any other tips regarding protecting the integrity of EE will be appreciated. One more question for anyone who can answer, which is less susceptible to corruption NVRAM or EEPROM. My EEPROM is internal to 68HC11. Regards, Musibau

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The EEPROM within the 68HC11 is extremely reliable, intrinsically. Anytime that you can use memory within the microcontroller, as opposed to outside, it's probably better because there is less exposure to transients outside the chip, on the traces running around the PC board. However wonder if you have got a low-voltage reset chip on your application, external to the 68HC11. If you do not have it, there is an excellent chance of corrupting EEPROM during power down cycles. There is a passage in the Pink Book that says one must have a low voltage reset circuit external to the 68HC11 for "nearly every application." On the checksum side, there are people better on software than I am. Typically one divides information that needs to be stored into EEPROM into logical groups, from several to many bytes, depending on how these groups are being used. You calculate the checksum on a group of bytes before storing the bytes into EEPROM. After reading the bytes back, you recalculate the checksum, and see if it matches what you read. If it doesn't, the corrective action taken depends on the application. Hope this is helpful. Best regards, Kerry Berland Silicon Engines 2101 Oxford Road Des Plaines, IL 60018 USA 847-803-6860 Fax 847-803-6870 ----- Original Message ----- From: Alowonle, Musibau To: m68HC11 (E-mail) Sent: Friday, August 16, 2002 10:09 AM Subject: [m68HC11] EEPROM protection Hello all, This is for all you software guru. Following is the problem: I suspect that I'm having some data corruption problem to my EEPROM (EE) and I would like to do a checksum to verify data integrity during write and read of the EE. I know how to do a checksum, but my problem is how I go about doing this. More specifically, where within my code (before read/write of EE) do I do the checksum. Any other tips regarding protecting the integrity of EE will be appreciated. One more question for anyone who can answer, which is less susceptible to corruption NVRAM or EEPROM. My EEPROM is internal to 68HC11. Regards, Musibau Yahoo! Groups Sponsor ADVERTISEMENT To unsubscribe from this group, send an email to: Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. [Non-text portions of this message have been removed]

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Thanks for your reply, the information you gave was very helpful. I do have one more question. Is it possible to corrupt the EE during write operation process (i.e. instead of writing 0xf0, 0xf1 got written) If this is possible how do you check for it? Best regards, Musibau -----Original Message----- From: Kerry Berland [mailto:] Sent: Friday, August 16, 2002 7:42 PM To: Subject: Re: [m68HC11] EEPROM protection The EEPROM within the 68HC11 is extremely reliable, intrinsically. Anytime that you can use memory within the microcontroller, as opposed to outside, it's probably better because there is less exposure to transients outside the chip, on the traces running around the PC board. However wonder if you have got a low-voltage reset chip on your application, external to the 68HC11. If you do not have it, there is an excellent chance of corrupting EEPROM during power down cycles. There is a passage in the Pink Book that says one must have a low voltage reset circuit external to the 68HC11 for "nearly every application." On the checksum side, there are people better on software than I am. Typically one divides information that needs to be stored into EEPROM into logical groups, from several to many bytes, depending on how these groups are being used. You calculate the checksum on a group of bytes before storing the bytes into EEPROM. After reading the bytes back, you recalculate the checksum, and see if it matches what you read. If it doesn't, the corrective action taken depends on the application. Hope this is helpful. Best regards, Kerry Berland Silicon Engines 2101 Oxford Road Des Plaines, IL 60018 USA 847-803-6860 Fax 847-803-6870 ----- Original Message ----- From: Alowonle, Musibau To: m68HC11 (E-mail) Sent: Friday, August 16, 2002 10:09 AM Subject: [m68HC11] EEPROM protection Hello all, This is for all you software guru. Following is the problem: I suspect that I'm having some data corruption problem to my EEPROM (EE) and I would like to do a checksum to verify data integrity during write and read of the EE. I know how to do a checksum, but my problem is how I go about doing this. More specifically, where within my code (before read/write of EE) do I do the checksum. Any other tips regarding protecting the integrity of EE will be appreciated. One more question for anyone who can answer, which is less susceptible to corruption NVRAM or EEPROM. My EEPROM is internal to 68HC11. Regards, Musibau Yahoo! Groups Sponsor ADVERTISEMENT To unsubscribe from this group, send an email to:

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