Suppose a ring oscillator is built from n inverters

Question

1. Design an asynchronously resettable D latch using logic gates.

2. Design an asynchronously resettable D flip-flop using logic gates.

3. Design a synchronously settable D flip-flop using logic gates.

4. Design an asynchronously settable D flip-flop using logic gates.

5. Suppose a ring oscillator is built from N inverters connected in a loop. Each inverter has a minimum delay of tcd and a maximum delay of t_pd. If N is odd, determine the range of frequencies at which the oscillator might operate.