Patent · US Expired

Rewriting protection of a size varying first region of a reprogrammable non-volatile memory

US5991849A · kind A · utility

65Cited by
9References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 8, 1997
Grant dateNov 23, 1999
Priority date
Expiry dateApr 8, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C16/22
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A program for rewriting data in an address region B is written in an address region A which can be rewritten by an external PROM writer. After resetting the microcomputer and rewriting the program in address region A, the reset state is cancelled and the last address in address region A of the EEPROM (1) is then stored in a register (17). An address detector (18) prohibits rewriting in address region A based on an address value stored in the register (17).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.