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US 11,635,464 B2Granted
Scan frame based test access mechanisms
AssigneeTexas Instruments Incorporated
InventorLee D. Whetsel
Life of this patent
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Abstract
Testing of an electrical device is achieved by providing a test access mechanism within the device that can receive scan frames from an external tester. The received scan frames contain stimulus data to be applied to circuitry within the device to be tested, a command for enabling a test control operation, and a frame marker bit to indicate the end of the scan frame pattern. The inputting of scan frames can occur continuously and simultaneous with a commanded test control operation.
Claims15
An integrated circuit comprising:
- (a) core circuitry having parallel scan paths, the parallel scan paths having serial stimulus inputs and serial response outputs;
- (b) a test serial input and a test serial output;
- (c) a scan input register having an input coupled to the test serial input and having scan parallel outputs coupled to the serial stimulus inputs;
- (d) comparator circuitry having parallel inputs coupled to the scan parallel outputs, having parallel inputs coupled to the serial response outputs, and having comparator outputs;
- (e) a fail bit register having inputs coupled to the comparator outputs and having a fail output;
- and
- (f) a frame count register having an input coupled to the fail output, and having an output coupled to an input of the fail bit register.
4 more elements
Dependencies are inferred from the claim text.