| 摘要 |
PURPOSE:To contrive the miniaturization and yield improvement of a one chip LSI by a method wherein an ROM and an RAM are formed in proximity resulting in common use for a part of a decoder, a selector, and a sense amplifier. CONSTITUTION:The RAM10 and the ROM11 are connected to the common decoder 12 by a common word select line; it is not necessary to have separate RAM decoder and ROM decoder, therefore a decoder is sufficient for two decoders, and then miniturization is enabled thereby. The word select line 30 from the decoder 27 comes to the ROM26 and the RAM25 in common. While, the figure signal line 31 of the RAM is connected to an RAM selector 28 and an RAM sense amplifier, and the figure signal line 31' of the ROM is connected to an ROM selector 28' and an ROM sense amplifier 29'. Therefore, at the time of the write and read-out of an RAM25 for example, since the word select line 30 is common, but the figure signal line 31 is separated, the cell at the intersection between the selected figure signal line and the common word select line 30 drives. |
