公开(公告)号：US5056110A

公开(公告)日：1991-10-08

申请号：US448715

申请日：1989-12-11

申请人： Timonty S. Fu ,  Allen W. Roberts

发明人： Timonty S. Fu ,  Allen W. Roberts

IPC分类号： G06F13/36 ,  H04L12/40

CPC分类号： H04L12/40006 ,  H04L25/0298

摘要： A solution to the problem in differential buses that the bus state for a given line pair is undefined when no unit is driving either of the bus lines in the pair. The lines in the bus pair are terminated to different voltage levels, thereby establishing a desired default condition when no unit is driving either line. The voltage offset between the two bus lines must be sufficient that differential receivers coupled to the bus when the bus is not driven can respond to the offset. At the same time, the offset must not be so great that a driver attempting to drive the bus pair cannot overcome the offset with enough margin for the receivers.