Boundary scan with ground bounce recovery
AssigneeAgilent Technologies, Inc.
InventorRaymond John Balzer
Life of this patent
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Abstract
A system for recovering from ground bounce during a boundary scan test is disclosed that includes operationally transitioning a Test Access Port controller from any of at least three undetermined controller states induced by the ground bounce to a determined controller state. The undetermined controller states may be selected from an UPDATE state, a RUN-TEST/IDLE state, a SELECT-DR-SCAN state, and a CAPTURE-DR state. The determined controller state can be the UPDATE-DR. Once in the determined controller state, the Test Access Port controller may also be operationally transitioned from an undetermined data state to a determined data state.
Claims26
A method of recovering from ground bounce during a boundary scan test, said method comprising the step of operationally transitioning a Test Access Port controller from any of at least three undetermined controller states induced by the ground bounce to a determined controller state.
A boundary scan apparatus with ground bounce recoverability comprising:
- at least one Test Access Port controller;
- and
- means for operationally transitioning the Test Access Port controller from any of at least three undetermined controller states induced by the ground bounce to a determined controller state.
A boundary scan apparatus with ground bounce recoverability, comprising:
- an in-circuit tester configured to provide a Test Access Port controller with a low Test Mode Select input prior to a transition from an update state;
- and
- said in-circuit tester further configured to operationally transition the Test Access Port controller from any of at least four undetermined controller states induced by the ground bounce to an UPDATE-DR state.
Dependencies are inferred from the claim text.