| 摘要 |
<p>PURPOSE:To obtain a read only memory (ROM) with a high speed and less power consumption, by using a dummy cell and a sense amplifier for a semiconductor mask ROM and eliminating a current continuously flowing by utilizing a main circuit as dynamic circuits entirely. CONSTITUTION:A dummy cell of a semiconductor mask ROM consists of transistors (TRs) 31-33 and 46-48, and a memory cell comprises TRs 35-38, 40 and 42 having larger mutual conductance than that for the above, and the memory cells 34, 39, 41, 43-45 store the information opposite to the said memory cells. Bit lines 75-80 are charged with precharge circuits 61-63. One of word lines 68-71, ... is selected with column selection circuits 81 and 82, and when the line 69, for example, is selected, a dummy word line 72 is selected via sense amplifiers 64-66 consisting of dynamic circuits. Thus, the potential of the lines 78 and 79 is fast fallen down in comparison with the potential of the lines 75- 77, the potential of a line 80 is made to precharge state and read out to readout lines 73 and 74 via the TRs 49-54.</p> |
