| 摘要 |
PURPOSE:To set an interval between fuses widely regardless of a decoder by providing a control circuit that includes fuses that is cut off corresponding to the defective address outside of a decoder, and controlling the decoder. CONSTITUTION:Plural decoder control circuits are provided in series connection, and a signal phi1 is outputted as a driving signal of the decoder. When an address corresponding to a defective memory is impressed from the external, points H, J, I, K, and M come in an H-level during a precharge period. During an active period, transistors Q10, Q11 are turned ON, however, since the fuse FA1 is cut off, the points I and K hold in the H-level and an address signal A1 is led, a point L comes to the H-level to turn a transistor Q16 ON. In case of the address corresponding to a defective memory, since all the transistors of respective control circuits corresponding to the transistor Q6 are turned ON, points Pn and P come to an L-level thereby causing the driving signal phi1 not to be outputted. As a result, the fuses can be disposed at the outside of the decoder, and the interval between the fuses can be set widely regardless of the decoder.
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