Secure storage of data in EEPROM e.g. in motor vehicle controller - comparing data with check word to ensure that storage cells found to be defective are not used for further operations

摘要

In an electrically erasable programmable read-only memory associated with a CPU, random-access memory and EPROM, the first ten storage addresses (FP1-FP10) are assigned to reception of error information, the next five addresses (CPA-CPE) are used for check sums, and the final address (DZP) houses a defect pointer. After a storage operation, the data and a check data word are compared and if any cell is defective a fresh first word is formed and inserted. USE/ADVANTAGE - In microprocessors of motor vehicle control equipment. Guarantees detection of defective cells in E2PROM, and practically eliminates loss of data.