| 摘要 |
PURPOSE:To output always <=1 driving control signal to prevent the destruction of circuits of tristate buffers, by providing a gate circuit on a driving control signal line so that tristate buffers are not operated simultaneously. CONSTITUTION:Three data inputs d1-d3 are inputted to a data bus 1 through tristate driving buffers 2-1-2-3, and the output of these inputs d1-d3 to the bus 1 is controlled by driving signals C1-C3 from driving control signal lines 4-1-4-3. These signals C1-C3 are inputted respective one inputs of AND circuits 3-1-3-3, and outputs on signal lines 4-1-4-3 are applied to the other inputs through a gate circuit consisting of resistances R1-R3, diodes D1-D4, a transistor TR1, etc. By signals C1-C3, buffers 2-1-2-3 are forcedly inhibited from being driven simultaneously, thus preventing the destruction of circuits connected to buffers 2-1-2-3. |
