Sequential Circuit: Counter Introduction Counter is a circuit which cycle through state sequence Two types of counter Synchronous counter (e.g. parallel) Asynchronous counter (e.g. ripple) Ripple counter let some flip-flop output to be used as clock signal source for other flip-flop Synchronous counter use the same clock signal for all flip-flop
Sequential Circuit: Counter Asynchronous Counter (Ripple) Example: 2-bit ripple counter Output from one flip-flop is connected to clock input for the next flip-flop MSB
Sequential Circuit: Counter Asynchronous Counter (Ripple) Example: 3-bit ripple counter
Sequential Circuit: Counter Asynchronous Down Counter The previous example is up asynchronous counter Down asynchronous counter count from large to zero and repeat Example: 3-bit binary down counter
Sequential Circuit: Counter Synchronous Counter (Parallel) Synchronous counter: flip-flop with the same synchronous clock signal We can build synchronous counter using process to design sequential circuit Example: 2-bit synchronous binary counter (using T flip-flop or JK)
Sequential Circuit: Counter Synchronous Counter (Parallel) Example: 2-bit synchronous binary counter (using T flip-flop or JK) cont….
Sequential Circuit: Counter Synchronous Counter (Parallel) Example: 3-bit synchronous binary counter (using T flip-flop or JK) cont…. YAMANI /ZAILY
Sequential Circuit: Counter Synchronous Counter (Parallel) Example: 2-bit synchronous binary counter (using T flip-flop or JK) cont….
Sequential Circuit: Counter Designing Synchronous Counter See sequential logic lecture notes Example: 3-bit Gray Code Counter (using JK flip-flop)
Sequential Circuit: Counter Designing Synchronous Counter 3-bit Gray Code Counter: flip-flop input
Sequential Circuit: Counter Designing Synchronous Counter 3-bit Gray Code Counter: logic diagram