| 摘要 |
<p>PURPOSE:To reduce the burden of a CPU by checking the number of times of writing to a memory block with an E<2>PROM itself, when the number of times of the writing exceeds the number of times set beforehand, notifying the excess to the CPU, and selecting the other memory block in the same chip. CONSTITUTION:The maximum number of times of the permitted writing to the memory block is set at a register 6 by the CPU. A memory circuit 5 counts and stores the output of a red/write control circuit 2 to which a write signal is inputted from the CPU. A comparing circuit 7 compares the register 6 with the contents of the memory circuit 5, when the register 6 corresponds to the contents of the memory circuit 5, the signal is outputted to an output terminal 8. Further, the output signal initializes the memory circuit 5, it is inputted to a selector circuit 9 to select the memory block, and the memory block is selected according to the output signal of the comparing circuit 7 by the selector circuit 9. Thus, the burden of the CPU can be reduced.</p> |
