Understanding Shift Register Configurations

A shift register is a type of sequential logic circuit constructed using flip-flops. Its primary function is to store and shift binary data from one flip-flop to the next with each clock pulse.

The Unique Feedback Connection

The question describes a specific configuration of a shift register where the output terminal of the final flip-flop in the chain is connected back to the input terminal of the first flip-flop. This creates a closed-loop system.

Identifying the Ring Counter

This feedback arrangement is the defining characteristic of a Ring Counter. In a ring counter:

• Data is shifted one position to the right (or left, depending on implementation) with each clock cycle.
• The output of the last flip-flop is directly connected to the input of the first flip-flop.
• This creates a circulating pattern of '1's and '0's. For example, if you load a single '1' into the register (e.g., 1000), after the first clock pulse it becomes 0100, then 0010, then 0001, and finally returns to 1000, completing the "ring".

Why Other Options Are Incorrect

Let's look at why the other options don't fit the description:

• BCD Counter: This is a counter that counts decimal numbers (0-9) using binary logic. It doesn't typically involve the specific shift register feedback loop described.
• Parallel Counter: This refers to counters where flip-flops can change state simultaneously based on specific logic, not the serial feedback loop mentioned.
• Ripple Counter: In a ripple counter, the clock signal is not directly connected to all flip-flops. Instead, the output of one flip-flop acts as the clock input for the next, causing a ripple effect. This differs from the direct feedback loop to the first flip-flop's input.

Therefore, the shift register configuration where the output of the last flip-flop connects to the input of the first is specifically known as a Ring Counter.