Final answer:
A bidirectional shift-register using a modulo-16 counter involves using D flip-flops and multiplexers, with the multiplexers controlling the direction of the data shift within the register.
Step-by-step explanation:
To create a bidirectional shift-register using a modulo-16 counter, we can utilize multiplexers and flip-flops. First, let's understand what each component does. A modulo-16 counter counts from 0 to 15 and then resets to 0, and a multiplexer (MUX) selects one of several input signals and forwards the selected input into a single line.
A bidirectional shift-register can shift data left or right depending on a control signal. To design this system, we can use D flip-flops connected in series to form the shift register. The number of flip-flops needed will be 4, as a modulo-16 counter represents 4 bits. Each flip-flop's data input (D) comes from the previous flip-flop's output (Q) when shifting right, or the next flip-flop's output (Q) when shifting left.
To control the direction, we would use two 4-to-1 multiplexers before each D flip-flop. The multiplexers will select either the right or the left neighboring flip-flop output based on the direction control signal. A high signal might indicate shifting right, with data flowing from D3 to D0, while a low signal would indicate shifting left, with data flowing from D0 to D3. Moreover, additional multiplexers would be necessary to load initial values into the register or clear it as required.
In summary, your bidirectional shift-register design can be built with a series of D flip-flops and controlled by 4-to-1 multiplexers, subject to the register being 4 bits wide as implied by a modulo-16 system.