SIMULTANEOUS BI-DIRECTIONAL I/O SYSTEM

摘要

A system for transmitting and receiving data between the near end to the far end of a transmission line. The system has simultaneous bi-directional (SBIDI) drivers and receivers for high performance over well behaved transmission lines. The SBIDI drivers and SBIDI receivers are enabled and disabled by logic inputs. A unidirectional (UNI) receiver is connected in parallel with each SBIDI receivers. Logic insures that the SBIDI and UNI receivers are not enabled at the same time. When desired, the SBIDI receivers are disabled and the UNI receivers enabled and signaling is done unidirectional. The current level in the SBIDI drivers may be modified in response to mode compensation signals to improve signal to noise in the unidirectional mode and to compensate for losses in the simultaneous bi-directional mode. The system may be integrated into all I/O's for maximum design flexibility.