| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit which has a fast operation speed an stably operates. SOLUTION: This semiconductor integrated circuit has three 1st logical operation circuits 1a, 1b, and 1c, keeper circuits 2a, 2b, and 2c which hold the output logic of the 1st logical operation circuits 1a, 1b, and 1c, three inverters IVa, IVb, and IVc which are connected to the output terminals of the 1st logical operation circuits 1a, 1b, and 1c. When the output of one of the 1st logical operation circuits goes down to a low level, the outputs of the remaining 1st logical operation circuits are forcibly set to a high level, so only one of the output terminals can be set to the high level. When the output A(0) of the 1st logical operation circuit 1a varies from the high level to the low level, corresponding PMOS transistors Q10 and Q11 turn off, so the those transistors Q10 and Q11 never impede the variation of the output of the 1st logical operation circuits 1a, so that the operation speed of the semiconductor integrated circuit becomes fast.
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