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Semiconductor memory device having data protection feature

  • US 5,991,197 A
  • Filed: 03/24/1998
  • Issued: 11/23/1999
  • Est. Priority Date: 10/17/1997
  • Status: Expired due to Term
First Claim
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1. A semiconductor memory device comprising:

  • a plurality of memory block regions, each memory block region including at least one memory block for storing data in a nonvolatile manner, each memory block region storing data of a different attribute;

    control circuitry for setting data rewriting protection status for said plurality of memory block regions on a region-by-region basis according to states of a plurality of external control signals, so that the protection status of one of said memory block regions can be made different from the protection status of another of said memory block regions.

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