| 摘要 |
<p>PROBLEM TO BE SOLVED: To minimize the increase of the chip size in a PROM-contg. microcomputer, with the high speed read request met by programmably varying the read speed according to the use of the contained PROM. SOLUTION: SEL signal is used to switch over one memory mode for storing one data in one memory cell 1 or 5 and another memory mode for storing one data in two cells (storing the actual value of data in the cell 1 and inverted value thereof in the cell 5). According to the memory mode switching, a data reading reference voltage is a predetermined fixed voltage at the one memory mode for storing one data in one cell, or a voltage given from the memory cell 5 for storing the inverted value of the data at the other memory mode for storing one data in two cells.</p> |
