| 摘要 |
PURPOSE:To attain a input/output operation at a normal part even if there is a partial fault and the remaining part is normal by providing a means controlling whether an input signal is inputted to the 2nd circuit section via the 1st circuit section or the input signal is inputted directly to the 2nd circuit section, selecting at least one of output signals of the circuit sections and outputting the signal externally. CONSTITUTION:A signal switching circuit 110 comprising logical gates 111a- 114b, output terminals 116a, b, 117a, b and switching signal input terminals 115a, b are inserted between an input circuit of four flip-flops circuit 101 of a pre- stage and four flip-flops circuit 102 of a post-stage in the titled circuit. When partial circuits 101, 102 are both not defective, a circuit having a function as a 8-stage shift register is realized by bringing the terminals 115a, 115b to ''0'', and when the circuit 102 is defective, the circuit 101 is operated by bringing the 115a to ''1'' and the 115b to ''0'' and a circuit extracting its output to the terminals 116a, b is realized. |
