Fault detection and bypass in a sequence information signal processor
First Claim
1. In a systolic array of identical, serially interconnected processor elements, a fault detection circuit comprising:
- a plurality of scan registers, each such scan register being associated with a respective one of said processor elements for shifting a plurality of selected test bits through a processor element and for generating a scan output signal from a processor element, said scan output signal being indicative of the logic performance of said processor element;
a comparator for generating an error signal when any such scan output signal is different from the remaining such scan output signals; and
an encoder for generating a plurality of encoded signals identifying the processor element for which such different scan output signal is generated.
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Abstract
The invention comprises a plurality of scan registers, each such register respectively associated with a processor element; an on-chip comparator, encoder and fault bypass register. Each scan register generates a unitary signal the logic state of which depends on the correctness of the input from the previous processor in the systolic array. These unitary signals are input to a common comparator which generates an output indicating whether or not an error has occurred. These unitary signals are also input to an encoder which identifies the location of any fault detected so that an appropriate multiplexer can be switched to bypass the faulty processor element. Input scan data can be readily programmed to fully exercise all of the processor elements so that no fault can remain undetected.
52 Citations
12 Claims
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1. In a systolic array of identical, serially interconnected processor elements, a fault detection circuit comprising:
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a plurality of scan registers, each such scan register being associated with a respective one of said processor elements for shifting a plurality of selected test bits through a processor element and for generating a scan output signal from a processor element, said scan output signal being indicative of the logic performance of said processor element; a comparator for generating an error signal when any such scan output signal is different from the remaining such scan output signals; and an encoder for generating a plurality of encoded signals identifying the processor element for which such different scan output signal is generated. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A fault detection circuit for use on a unitary integrated circuit chip with a plurality of identical processor elements configured in a serial arrangement and forming a systolic array;
- the fault detection circuit comprising;
a plurality of scan registers, each such scan register being associated with a respective one of said processor elements for shifting a plurality of selected test bits through a processor element and for generating a scan output signal from a processor element, said scan output signal being indicative of the logic performance of said processor element; a comparator for generating an error signal when any such scan output signal is different from the remaining such scan output signals; and an encoder for generating a plurality of encoded signals identifying the processor element for which such different scan output signal is generated. - View Dependent Claims (8, 11, 12)
- the fault detection circuit comprising;
- 9. The fault detection circuit recited in claim B wherein said switching means comprises a switching signal terminal on each said multiplexer and a register for storing a plurality of switching signals, said switching signals being applied to respective ones of said switching signal terminals, the state of each such switching signal being controlled in accordance with the plurality of encoded signals generated by said encoder.
Specification