| 摘要 |
The memory is divided into two regions, with protection word determining which is to be protected. The electrically programmable and erasable, nonvolatile ROM comprises either individual or block addressable memory registers. It also includes a protection register in which a protection word may be written. This protection word comprises a given number of bits for coding the address of the memory register, or a block of memory registers, called the address limit. This divides the memory space into a lower zone and an upper zone, and a zone bit whose value determines which of these two zones of the memory is able to be protected against writing. User is offered choice of which zone of memory is to be protected.
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