However, as can be seen from Table 1, signal f2 becomes 1 in functional mode FC7 and the intermediate terminals R4 and R5 are respectively conducted to the input terminals X0 and X2 via the tri-state buffers 11 and 12, thus causing the input terminals X0 and X2 to function as the output terminals.The terminals X0 and X2 are used, of course, as the input terminals in functional modes other than F