| 摘要 |
PURPOSE:To eliminate the need for a termination resistor required conventionally and to attain high speed transmission by adding a tri-state gate giving logical 1 when no signal is transmitted to a signal transmission circuit comprising plural 3-state gates of dot-OR connection. CONSTITUTION:Input signals a'-C', d'-f', and also control signals (a-c), (d-f) are inputted to tri-state gates A-C, D-F to apply the input signals selectively to an AND gate 4. An input signal of level '1' is always applied to tris-stage gates G, H and control signals g, h at high level when the other control signals (a-c) and (d-f) are at a low level are applied to the gates G, H so that he terminals 1, 2 are never brought into a high impedance when all of the tri-state gates are all reset. Thus, no termination resistor preventing high impedance is required and the level of the terminals 1, 2 is brought quickly into '1' level when the circuit changes to non-transmission state.
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