Which device is typically used to implement a memory element capable of storing a single bit and is clocked for state changes?

Which device is typically used to implement a memory element capable of storing a single bit and is clocked for state changes?

• A. D Flip-flop
• B. Latch
• C. Counter
• D. J-K Flip-flop

Answer: (D)

A memory element that stores a single bit and changes state only on a clock edge is a flip-flop. The J-K flip-flop is a flexible, edge-triggered memory element that uses two inputs, J and K, along with a clock to determine its next state. On a clock transition, the outputs update according to the combination of J and K: both low holds the current state, J high and K low sets the bit, J low and K high resets it, and both high toggles the stored bit. This edge-triggered operation provides reliable, synchronized storage, which is essential in sequential circuits. The J-K flip-flop’s versatility—able to perform set, reset, hold, and toggle—makes it a robust choice for implementing a single-bit memory element in many designs, and it can even emulate a D flip-flop if needed. In contrast, a latch is level-sensitive and can change state as long as its enable is active, which is less suitable for stable memory in synchronous systems. A counter, meanwhile, is typically used to store multiple bits and perform counting operations, not to store a single bit in a standalone memory element.

A memory element that stores a single bit and changes state only on a clock edge is a flip-flop. The J-K flip-flop is a flexible, edge-triggered memory element that uses two inputs, J and K, along with a clock to determine its next state. On a clock transition, the outputs update according to the combination of J and K: both low holds the current state, J high and K low sets the bit, J low and K high resets it, and both high toggles the stored bit. This edge-triggered operation provides reliable, synchronized storage, which is essential in sequential circuits.

The J-K flip-flop’s versatility—able to perform set, reset, hold, and toggle—makes it a robust choice for implementing a single-bit memory element in many designs, and it can even emulate a D flip-flop if needed. In contrast, a latch is level-sensitive and can change state as long as its enable is active, which is less suitable for stable memory in synchronous systems. A counter, meanwhile, is typically used to store multiple bits and perform counting operations, not to store a single bit in a standalone memory element.