| 摘要 |
PURPOSE:To make data read/write possible only when procedures of the access coincide with preliminarily determined procedures, by discriminating whether they coincide with each other or not by a memory access controller. CONSTITUTION:A memory device body 1 is set to a host system 3. For the purpose of making the device 1 usable, procedures determined preliminarily between the device 1 and its owner, namely, an external device are executed between a memory access controller 4 and the host system 3. The controller 4 enables a memory control signal D after confirming the validity. Then, an internal memory 2 can be accessed, and the normal memory access is performed hereafter. Though the normal memory access is possible in the memory device body 1 when it is made accessable once, procedures for the memory access are complicated to protect the memory in various levels.
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