Circuit and method for diagnosing scan chain failures
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorSandeep Kumar Goel
Life of this patent
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Abstract
A circuit includes a plurality of scan chains arranged in a ring network topology. Each scan chain includes a plurality of scan blocks, each of the plurality of scan blocks including a storage element and a switching device. Each switching device includes a first input configured to receive an output of a storage element in a different scan chain from the scan chain in which the switching device is disposed, and a second input configured to receive one of a function logic signal or a test scan signal. The switching device configured to selectively couple the first input or the second input to an input of the storage element.
Claims19
A circuit, comprising:
- a plurality of scan chains arranged in a ring network topology, each scan chain including a plurality of scan blocks, each of the plurality of scan blocks including a storage element and a switching device,
- wherein the storage element comprises a first input for receiving a functional logic signal and a second input for receiving a test scan signal, and
- wherein the switching device includes a first input configured to receive an output of a storage element in a different scan chain from the scan chain in which the switching device is disposed, a second input configured to receive the test scan signal, and an output coupled to the second input of the storage element.
A circuit, comprising:
- a plurality of scan chains coupled to a function logic and arranged in a ring network topology, each scan chain comprising a plurality of scan blocks that are coupled to one another, each of the plurality of scan blocks comprising a flip-flop circuit and a multiplexer,
- wherein the flip-flop circuit comprises a first input for receiving a functional logic signal and a second input for receiving a test scan signal, and
- wherein the multiplexer comprises a first input configured to receive an output of a flip-flop circuit in a different scan chain from the scan chain in which the multiplexer is disposed, a second input configured to receive the test scan signal, and an output coupled to the first input of the flip-flop circuit, the multiplexer configured to selectively couple the first input or the second input to the first input of the flip-flop circuit.
A circuit, comprising:
- a plurality of scan chains arranged in a ring network topology, each scan chain including a plurality of scan blocks, each of the plurality of scan blocks including a storage element and a switching device,
- wherein the storage element comprises a first input configured to directly receive a functional logic signal from a function logic and a second input configured to receive a test scan signal, and
- wherein the switching device includes a first input configured to receive an output of a storage element in a different scan chain from the scan chain in which the switching device is disposed, a second input configured to receive the test scan signal, and an output coupled to the second input of the storage element.
Dependencies are inferred from the claim text.