| 摘要 |
PURPOSE:To improve the reliability of a test of contention operation by discriminating the occurrence state of contention by the contents of a display register for the contention state, and deciding whether the processing result of a contention arranging circuit is proper or not. CONSTITUTION:The contention arranging circuit BA is provided with, for example, three gate circuits G1-G3, to which three kinds of processing request A, B, and C are inputted to output bus use permit signals (a), (b), and (c). Further, a contention display circuit AP is provided with a decoder DEC and four contention display registers REG1-REG4 corresponding to the three kinds of request, and the requests A-C are inputted to the circuit AP and decoded by the decoder DEC to be set in registers REG1-REG4. Namely, the requests are set in the register REG1 when A, B, and C content with one another, in the register REG2 when A and B, in the register REG3 when A and C, or in the register REG4 when B and C. Consequently, it is judged whether contention arrangement processing is performed or not, so the contention operation is confirmed easily. |
