| 摘要 |
PURPOSE:To obtain a microcomputer with high reliability by providing the same number of redundancy bits to an ALU, data bus and each register. CONSTITUTION:The 1st switching circuit 9 saving a defective bit, replacing it into a redundancy bit and switching the circuit so as to input/output a normal bit only is provided between a register 4 for an input/output port and an input/ output circuit 6, furthermore the 2nd switching circuit 10 saving a defect bit, replacing it into a redundancy bit and switching it so as to input/output a normal bit is provided similarly between a register 3 for instruction storage and a control circuit 5. Moreover, a saving circuit 11 to replace the defective bit into the redundancy bit is provided in the inside of the ALU1. Then the 1st and 2nd switching circuits 9, 10 and the saving circuit 11 are controlled by switching with a switching signal S formed on the basis of the result of test at the manufacture of the microcomputer. |
