Serial scan chain in a star configuration
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.
Claims13
A method implemented to test a plurality of components coupled in a star configuration, each component having a test access port (TAP) controller, comprising:
- performing a capture phase of a scan operation on all of the TAP controllers in the star configuration;
- sequentially selecting one of said TAP controllers at a time to perform a shift state;
- and
- when all of said TAP controllers have been sequentially selected to perform the shift phase, selecting all of the TAP controllers to perform an update phase.
A system, comprising:
- a debug test system (DTS);
- and
- a plurality of target systems (TS) coupled to said DTS via a test communication link in a star configuration, each TS having a test access port (TAP) controller coupled to said test communication link;
- wherein said DTS causes all of the TAP controllers to concurrently perform a capture state in which all of the TAP controllers acquire new data and also to transition to a pause state, and wherein the DTS sequentially selects one TAP controller at a time to shift data out of the selected TAP controller while the other TAP controllers remain in the pause state.
Dependencies are inferred from the claim text.