Patent ID: 8161367

Claim:
Sequential storage circuitry for an integrated circuit, comprising: storage circuitry comprising: a first storage element for storing, during a first phase of a clock signal, a first indication of an input data value received by said sequential storage circuitry; a second storage element coupled to an output of said first storage element, for storing a second indication of said input data value during a second phase of said clock signal; and error detection circuitry for detecting a single event upset error in any of said first and second storage elements comprising: two additional storage elements for storing third and fourth indications of said input data value respectively in response to a pulse signal derived from said clock signal; comparison circuitry for comparing said third and fourth indications of said input data value; and further comparison circuitry for comparing during a first phase of said clock signal said first indication and at least one of said third and fourth indications, and for comparing during a second phase of said clock signal said second indication and at least one of said third and fourth indications; and output circuitry for correcting any detected errors in said storage circuitry and for outputting an output value; said output circuitry being responsive to no match by said comparison circuitry to output said first indication during a first phase of said clock signal and said second indication during said second phase of said clock signal, and said output circuitry being responsive to a match by said comparison circuitry to output a value in dependence upon comparisons performed by said further comparison circuitry; said output circuitry being responsive to a match by said further comparison circuitry during a first phase of said clock signal to output said first indication during said first clock cycle and to a no match to output an inverted value of said first indication; and said output circuitry being responsive to a match by said further comparison circuitry during a second phase of said clock signal to output said second indication during said second phase of said clock signal and to a no match to output an inverted value of said second indication.