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Robustness Update Protocol on Rewritable ROM Disclosure Number: IPCOM000015331D
Original Publication Date: 2001-Nov-19
Included in the Prior Art Database: 2003-Jun-20
Document File: 3 page(s) / 46K

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Disclosed is a method to avoid data corruption on a rewritable ROM due to

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Robustness Update Protocol on Rewritable ROM

Disclosed is a method to avoid data corruption on a rewritable ROM due to

power fail during rewrite operation.

Some rewritable ROM is often employed as one of program memory on a device. Such program memory has a chance to be reprogrammed at field for version up.

It is possible that the reprogramming is terminated by an accident like power down. Generally such data corruption causes malfunction of the device. To avoid such data corruption it is general to employ ECC (Error Correction Code) to detect and

correct the corrupted data. However, the correction capability has a limitation and the length of correctable data is limited. On such reprogramming it is general that the whole memory is reprogrammed. On this case ECC is ineffectual because the whole last data is not updated on sequential update from the top of memory.

The key point of the present disclosure is to update the number of correctable bytes of the program data and ECC alternately. It is now supposed that the correction capability is N bytes and the ECC is located on the bottom of the memory. First, the memory image of which N bytes are updated needs to be prepared. Next, ECC for the updated memory image shall be generated. Then the N bytes of memory and ECC shall be updated sequentially. Continuously the next N bytes shall be updated with the new ECC image. According to this algorithm the corrupted data is less than correction capability even if such power...