PURPOSE: To improve a wave shape distortion and to eliminate the identification error of a digital signal by connecting a prescribed resistance to respective patterns when a first and second signal patterns of a parallel connecting are provided between a first and second logical integrated circuits.

CONSTITUTION: At the time of designing a signal pattern, all the designing aims of the width of a pattern, the thickness of dielectric between earth patterns and the dielectric constant of the dielectric, etc., is determined, however, at the time of manufacturing, it is difficult to do it as this, accordingly, a mismatching is generated between the terminal resistance selected at the time of the designing and the real signal pattern and a distorting component is generated. Thus, in order to resolve this, a circuit is constituted as follows. Namely, one edge A of the first signal pattern is directly connected to the first logical integrated circuit 1, one edge C of the second signal pattern is connected through a first resistance R1 to the first logical integrated circuit 1 respectively and other edges B and D are connected through a third resistance R3 serially connected and a fourth resistance R4 to the second logical integrated circuit 2. The other edge B is connected to a grounding resistance R2 extending from the resistance R.