Please explain every line.

A digital control circuit has three inputs: Start, Stop and Clock, as well as an output signal Run. The Start and Stop signals are of indeterminate duration and may span many clock cycles. When the Start signal goes to 1 , the circuit must generate Run=1. The Run signal must remain high until the Stop signal goes to 1, at which time it has to return to 0. All changes in the Run signal must be synchronized with the Clock signal. (a) Design the desired control circuit. (b)Write VHDL code that specifies the desired circuit