US Patent 7793181 Sequential storage circuitry for an integrated circuit

Sequential storage circuitry is provided for an integrated circuit, comprising input circuitry, a storage structure, and output circuitry. The input circuitry receives an input data value to the sequential storage circuitry, and generates an internal data value. The input circuitry receives a first control signal which when asserted causes it to generate as the internal data value an inverted version of the input data value, and which when not asserted causes the input circuitry to generate as the internal data value the input data value. The storage structure then stores an indication of the internal data value. The output circuitry generates, from the indication of the internal data value stored in the storage structure, an output data value for outputting from the sequential storage circuitry. More particularly, the output circuitry receives a second control signal derived from the first control signal, which causes the output circuitry to generate as said output data value an inverted version of the internal data value in the event that the input circuitry generated as the internal data value an inverted version of the input data value, and otherwise generates as the output data value the internal data value.