| 摘要 |
PROBLEM TO BE SOLVED: To decrease the number of input/output terminals for an operation test by connecting an input/output terminal for a test to a code path and inputting an instruction code to a CPU, and connecting the test input/output terminal to the output terminal of the CPU and outputting the execution result of the CPU. SOLUTION: A bus interface unit(BIU) 4 receives an input request for an instruction code from the CPU 6 and a switch control circuit 5 turns on a switch S2 to connect an I/O circuit 3 to the code path. A tester 1 outputs the instruction code, which is inputted from the test input/output terminal 2. The CPU 6 acquires the instruction code through the code path and executes the instruction code. The BIU 4 receives an output request for the execution result from the CPU 6 and the switch control circuit 5 turns on a switch S5 to connect the output terminal 8 of the CPU 6 to the I/O circuit 3. The CPU 6 outputs the execution result of the instruction code to the tester 1 through the test input/output terminal 2. |
