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.
Claims13
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 each storage element comprises a first input for receiving a function logic signal and a second input for receiving a test scan signal, and
- wherein 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, a second input configured to receive the function logic signal, and an output coupled to the first input of the storage element, the switching device configured to selectively couple the first input or the second input to the first input of the storage element.
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 function logic signal, and an output coupled to the first input of the storage element.
A circuit, comprising:
- a plurality of scan chains coupled to the function logic and arranged in a ring network topology, each scan chain including a plurality of scan blocks that are coupled to one another, each of the plurality of scan blocks including 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 function logic 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.
Dependencies are inferred from the claim text.