A 4-bit up/down binary counter is in the DOWN mode and in the 1100 state. To what state does the counter go on the next clock pulse?
A. 1101
B. 1011
C. 1111
D. 0000
A 4-bit ripple counter consists of flip-flops, which each have a propagation delay from clock to Q output of 15 ns. For the counter to recycle from 1111 to 0000, it takes a total of ________.
A. 15 ns
B. 30 ns
C. 45 ns
D. 60 ns