Moving third tap controller from exit2-DR state to pause-DR state
AssigneeTexas Instruments Incorporated
InventorGary L. Swoboda
Life of this patent
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Abstract
A method implemented to test a plurality of components coupled in a star configuration, each component having a test access port (TAP) controller. The method comprises performing a capture phase of a scan operation on all of the TAP controllers in the star configuration and sequentially selecting one of the TAP controllers at a time to perform a shift state. When all of the TAP controllers have been sequentially selected to perform the shift phase, the method further comprises selecting all of the TAP controllers to perform an update phase.
Claims4
A process of testing target systems connected in a star configuration, each target system having a test access port controller, comprising:
- A. moving all of the TAP controllers from a RunTest/Idle state, through a Capture-DR state and an Exit1-DR state into a Pause-DR state without traversing a Shift-DR state;
- B. selecting a first TAP controller with first encoded bits on a TDI input to each target system;
- C. moving only the first TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state;
- D. de-selecting the first TAP controller and selecting a second TAP controller with second encoded bits on the TDI input to each target system;
- E. moving only the second TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state;
- F. de-selecting the second TAP controller and selecting a third TAP controller with third encoded bits on the TDI input to each target system;
- G. moving only the third TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state;
- and
- H. selecting all of the TAP controllers with encoded bits on the TDI input to each target system and moving all of the TAP controllers from the Pause-DR state to an Update-DR state.
Dependencies are inferred from the claim text.