Digital in-circuit tester having a channel-driver inhibitor.

摘要

A digital in-circuit tester has a test-head controller which controls driver-receiver channels for driving contact elements of the device under test, and for receiving signals from the contact elements. At least one driver-receiver channel has both a driver and a receiver. The driver includes a data-state-retention means for generating the state to which a corresponding contact element will be driven. The driver also includes a driver-enable-state-retention means for enabling the driver to drive the corresponding contact element. The driver also includes a inhibitor-state-retention means responsive to a driver-enable-nullify instruction from the test-head controller for nullifying the action of the driver-enable-state-retention means, thereby allowing the receiving to receive a signal from the corresponding contact element.