Transmitter and receiver circuits for high-speed parallel digital data
transmission link

    公开(公告)号:US5978419A

    公开(公告)日:1999-11-02

    申请号:US881471

    申请日:1997-06-24

    CPC分类号: H04L25/14 G06F1/12 H04L1/24

    摘要: An information transfer system includes a transmitter and a receiver for transferring information over a differential communication link. The transmitter circuit includes a plurality of gated driver circuits each associated with one of a plurality separate phases of a clock signal, all of the gated driver circuits having respective outputs connected to a differential driver. Each gated driver circuit receives at a respective input a respective one of a plurality of selected information signals and transmits it over the communication link in response to the associated clock signal phase. A plurality of information selectors, each associated one of the gated driver circuits, are connected to receive a plurality of information signals each from a respective one of a plurality of digital information sources and selectively couple one of the information signals to the associated gated driver circuit as the respective selected information signal during a clock signal phase ahead of the clock signal phase ahead of the clock signal phase with which the associated gated driver circuit is associated. The receiver circuit includes a differential receiver which generates a single-ended signal representative of digital data in response the differential signals transmitted over the wires comprising the differential communication link. The differential receiver has a plurality of inputs each for connection to one of the wires of the differential communication link. A termination resistor is connected between the differential receiver inputs, and a continuity test circuit applies a test voltage to one of the differential receiver inputs during a link test operation. The digital receiver generates the single ended signal representative of digital data provided by the transmitter circuit the appropriate digital data value if the wires are continuous between the transmitter circuit and the receiver circuit. However, if at least one of the wires is not continuous, the differential receiver will provide a single-ended signal representative of the wrong digital data value.