【单选题】A positive edge-triggered J-K flip-flop is used to produce a two-phase clock. However, when the circuit is operated it produces erratic results. Close examination with an oscilloscope reveals the pres...
A.
A race condition exists between the Q and Q outputs to the AND gate.
B.
A race condition exists between the CLOCK and the outputs of the flip-flop feeding the AND gate.
C.
The PRESET and CLEAR terminals may have been left floating.
D.
A race condition exists between the J and K inputs.
【单选题】Choose the one that best completes each of the following statements according to the text. When the circuit is broken anywhere, the circuit will stop carrying a _____.