Patent ID: 7123069

Claim:
A circuit device, into which a first input signal and a second input signal are entered, comprising: a first switching array to detect which of the two input signals is the first to change its state, comprising a first flip-flop which outputs first and second flip-flop output signals; a second switching array, which emits an output signal, which, when the first input signal first changes its state, only changes its state in reaction to a change in the state of the second input signal, and, when the second input signal first changes its state, only changes its state in reaction to a change in the state of the first input signal, the second switching array comprising second and third flip-flops, and first and second NAND gates, the first NAND gate at a first input receiving the first flip-flop output signal, and the second NAND gate at a first input receiving the second flip-flop output signal, the second flip-flop outputting a third flip-flop output signal to a second input of the first NAND gate to control whether or not the first flip-flop output signal of the first flip-flop is to be relayed via the first NAND gate to the second flip-flop, and a fourth flip-flop output signal to a second input of the second NAND gate to control whether or not the second flip-flop output signal of the first flip-flop is to be relayed via the second NAND gate to the second flip-flop, the second flip-flop comprising third and fourth NAND gates with at least three inputs each.