Patent ID: 7768312

Claim:
A semiconductor device comprising: a driver section for transmitting data to a data transmission line in which power supply termination is made, wherein said driver section includes: a plurality of transistors which are provided on a pull-up side and have different ON resistance values to drive said data transmission line in a high level; a plurality of resistance elements which are provided on said pull-up side and each of which is connected in series to each of said transistors and has one end connected to an output side of said transistor and the other end connected to said data transmission line; a plurality of transistors which are provided on a pull-down side and have different ON resistance values to drive said data transmission line in a low level; a plurality of resistance elements which are provided on said pull-down side and each of which is connected in series to each of said transistors and has one end connected to an output side of said transistor and the other end connected to said data transmission line; and a driving transistor selecting section which selects any of said plurality of transistors on each of said pull-up side and said pull-down side, wherein: said plurality of said transistors provided on said pull-up side are P-channel transistors; said plurality of said transistors provided on said pull-down side are N-channel transistors; and each of said plurality of said resistance elements is connected in series to each of said N-channel transistors and has said one end connected to an output side of said N-channel transistor, and wherein: said plurality of said transistors include a first group of said P-channel transistors of which sources are connected to a power supply side and drains are commonly connected, a second group of said P-channel transistors for resistance element selection of which sources are connected to drain sides of said first group and drains are commonly connected to said data transmission line through resistance elements having different resistance values interposed therebetween, a third group of said N-channel transistors of which sources are connected to a ground side and drains are commonly connected, and a fourth group of said N-channel transistors for resistance element selection of which sources are connected to drain sides of said third group and drains are commonly connected to said data transmission line through resistance elements having different resistance values interposed therebetween; said driving transistor selecting section selects any of said first group and any of said third group by changing gate levels of said transistors of said first group and said third group; and said semiconductor device further comprises a resistance transistor selecting section which selects any of said second group and any of said fourth group to select a resistance element by changing gate levels of said transistors of said second group and said fourth group.