Patent ID: 7443212

Claim:
A semiconductor integrated circuit comprising: an input circuit that receives input signals supplied from an external terminal; a terminal circuit that is connected to the external terminal and includes plural MOSFETs connected in parallel; and a control means that controls the number of the plural MOSFETs to be turned on to control a resistance value of terminal resistance, wherein the plural MOSFETs comprise a first MOSFET of a first conduction type disposed at power voltage side and second MOSFET of a second conduction type disposed at a ground potential side of the terminal circuit, wherein the first MOSFET and the second MOSFET are connected by one straight wiring to form a layout of a basic structure, two or more of the basic structures comprising the first MOSFET and the second MOSFET are disposed in parallel in a stripe form in a direction orthogonal to the wiring, wherein the control means includes a resistance element connected to the external terminal, and forms a signal for selecting the first MOSFET and the second MOSFET so as to produce a resistance value closest to a resistance value of the resistance element connected to the external terminal, wherein the first MOSFET and the second MOSFET respectively comprise plural pieces having an on-state resistance value of a binary weight, and are selectively turned on by a selection signal of binary code formed by the control means, wherein each of the first MOSFET and the second MOSFET comprises first plural pieces whose on-state resistance values have weights of low-order bits of the binary code, and second plural pieces each having the same on-state resistance value assigned to high-order bits of the binary code, and low-order bits of the selection signal of binary code formed by the control means are used to select corresponding MOSFETs of the first plural pieces from among the plural pieces of the first MOSFET and the second MOSFET, and code corresponding to the high-order bits is supplied to a decoder circuit and used to select corresponding MOSFETs of the second plural pieces.