Circuit To Facilitate Testing Of Bidirectional Test Points
Original Publication Date: 1979-Mar-01
Included in the Prior Art Database: 2005-Feb-20
New large-scale integration circuits and single-chip microprocessors have encourgaged bus-oriented system designs. The high density packaging often leaves only the bus for data transfer and testing. Typically, a logic tester is designed to drive all known logic families and future technologies. This general application design requires that the drivers be capable of sourcing current or sinking current depending on the drive level and the technology. This has been successfully done. The added requirement that the driver be capable of sourcing or sinking current which can be turned off without disturbing the state of the bus has been a continuing and perplexing problem. Typically the driver will cause a "glitch" or voltage spike during "turn-off" which upsets the known state of the unit under test.