VHDL Code for 4-bit Ring Counter and Johnson Counter

VHDL Ring Counter 4 bit

Ring Counter very similar to shift register. At each clock pulse, data at each flipflop shifted to next flipflop with last output is feed back to the input of first flipflop. Also the first flop is set to ‘1’ at the reset state. so it shift bit ‘1’ to next flipflop for each clock input and repeat the sequence as shown below.