| 摘要 |
PURPOSE:To permit ROM and RAM to coexist in the same address space by modifying some of memory cells, forming an RAM storage device, into ROM to be used. CONSTITUTION:Short-circuit line SL is connected to one part of an RAM cell forming a semiconductor RAM storage device to short-circuit one load resistance R2, and then storage contents via cross transistors T1 and T2 are fixed to form ROM cell MC11, so that ROM cells MC11... will coexit in the address space with RAM cells MC12, MC21, MC22.... Thus, the address space is utilized effectively and the operation speed of ROM is increased. |
