| 摘要 |
PURPOSE:To take measures to select a higher-priority signal and to preclude a bus fight completely by detecting conditions by a bus fight detecting means previously. CONSTITUTION:Two drive signals 14 and 24 supplied from a testing device 3 are branched and inputted to a NAND circuit 31 in the bus fight condition detection part 6 and when the simultaneous generation of both signals is detected, a low level is outputted to one input terminal of an AND circuit 32 in a priority selection part 7 while a clock 15 is inhibited from being inputted to the other input terminal. Its output is inputted to the clock terminal of a flip-flop 13 to stop the driver signals from being sent out to a driver 11. Therefore, the driver signal 24 is selected preferentially and outputted through a flip-flop 23 with a clock 25 to drive a driver 21. Consequently, the bus fight is precluded completely. |
