Exclusive-or gate for use in delay using transmission gate circuitry
AssigneeFujitsu Limited
InventorHiroshi Yamazaki
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Abstract
An exclusive-OR circuit is for use in a delay device outputting a signal delayed from an input signal. The exclusive-OR circuit comprises an odd number of inverters, an even number of inverters, and a two-input selector. In the two-input selector, an inversion control signal for determining whether to invert a signal to be output, is input to one of input terminals via the odd number of inverters, and input to the other of the input terminals via the even number of inverters, and the input signal is supplied to a control terminal as a control signal for determining which of two signals input to the input terminals is output.
Claims6
An exclusive-OR circuit receiving an inversion control signal and an input signal, said exclusive-OR circuit for use in a delay device and comprising:
- an input terminal inputting the inversion control signal, said inversion control signal indicating whether to output by said exclusive-OR circuit a circuit output signal logically the same as the input signal or logically inverted from said input signal;
- an odd number of inverters coupled to the input terminal and including a last stage inverter;
- an even number of inverters coupled to the input terminal, configured separately from said odd number of inverters, and including a last stage inverter such that a delay time of the signal logically the same as the input signal is equal to a delay time of the signal logically inverted from the input signal, said last stage inverter of said even number of inverters having the same delay characteristics for a load as the last stage inverter of said odd number of inverters;
- and
- a two-input selector coupled to the last stage inverter of the odd number of inverters and to the last stage inverter of the even number of inverters, inputting the input signal, the output signal from said odd number of inverters, and the output signal from said even number of inverters, and outputting the circuit output signal logically the same as said input signal or the circuit output signal logically inverted from said input signal, based on said input signal, the output signal received from the last stage inverter of said odd number of inverters, and the output signal received from the last stage inverter of said even number of inverters.
An exclusive-OR circuit, for use in a delay device, to which are input an input signal and an inversion control signal determining whether to output a signal logically the same as said input signal or, alternatively, a signal logically inverted from said input signal, said exclusive-OR circuit comprising:
- a first inverter inputting a signal logically the same as said inversion control signal, said first inverter being a last stage inverter of an odd number of inverters coupled in series to each other;
- a second inverter inputting a signal logically inverted from said inversion control signal, said second inverter being a last stage inverter of an even number of inverters coupled in series to each other, said second inverter including the same delay characteristics for a load as said first inverter such that a delay time of the signal logically the same as the input signal is equal to a delay time of the signal logically inverted from the input signal;
- and
- a two-input selector, coupled to the first inverter and to the second inverter, to which said input signal, an output signal from said first inverter, and an output signal from said second inverter are input, said two-input selector outputting the signal logically the same as said input signal or the signal logically inverted from said input signal.
Dependencies are inferred from the claim text.