| 摘要 |
<p>PURPOSE:To constitute an ROM cell with a single transistor without using a complicated circuit by controlling each word line and a common bit line of an ROM cell consisting of p and n channel transistors. CONSTITUTION:A transistor TR33 is turned on with a clock CK1, and a bit line BL connected in common to n and p channel TRQN and QP forming ROM cells 11A and 11B is precharged. Then a TRQ3 is turned off and the line BL is set in a floating state. While a discharging TRQ1 is turned off with a clock CK3 with a transmission gate TQ1 turned on respectively. Then a work line WLN becomes active and the cell 11A connected to the line WLN is selected. Thus the data stored to the cell 11A are read out via a sense amplifier 13, etc. In the same way, the one-bit information of cells 11A and 11B are read out onto a common bit line with different timings. Thus it is possible to constitute an ROM cell with a single transistor in a simple constitution.</p> |
