| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique of designing ASIC which can check faulty soldering. SOLUTION: The ASIC 1 consists of an ordinary circuit 3, a selector circuit 5 which selects an output signal of the ordinary circuit 3 or an output signal of a CPU interface circuit 4, tristate buffers 6a, 6b and 6c which can regulate output of the selector circuit 5 to a high impedance, the CPU interface circuit 4 which regulates the selector circuit 5 and the tristate buffers 6a, 6b and 6c and a bus 7 which sends/receives an address and data to/from the CPU interface circuit 4. Meanwhile, ASIC 2 consists of an ordinary circuit 8, a CPU interface circuit 9 which monitors an input level of an external input circuit and a bus 10 which sends/receives an address and data to/from the CPU interface circuit 9. |
