| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a memory device which can read out information having high speed and high reliability, in some parts of a memory and having high information storage density, in other parts of the memory. SOLUTION: A multi-level memory device has a memory section (multilevel array), including cells being programmable with the prescribed number of level being larger than 2 and a memory section (bilevel array), including cells being programmable with the number of level of 2. The multilevel array is used for storing high density data, in which read speed is not essential such as storing an operation code of a system, including a memory device. The bilevel array is used for storing data required to have high speed and reliability, such as BIOS of a personal computer and data stored in a cache memory, in which the read-out speed is essential such as, storing an operation code of a system, including a memory device. A circuit part, being exclusive for all the functions required for programming, writing of test instructions, and operation of a memory device is common to both arrays.</p> |
