Which device stores the status of its D input when the clock makes a transition?

Which device stores the status of its D input when the clock makes a transition?

• A. Flip-flop
• B. Data-type Latch
• C. NOR Logic Gate
• D. OR Logic Gate

Answer: (B)

The key idea is how a storage element captures and holds data when the clock changes. A D-type latch is designed to latch the D input and store that value at the moment the clock transitions, and then retain it until the next transition. That behavior makes it the element that records the D value at clock events, which is why it’s the best choice in this context. In contrast, a NOR or OR gate is purely combinational and does not store state, so they cannot hold the D input over time. The flip-flop also stores data on a clock edge, but the question’s phrasing is typically associated with the latch’s behavior in many practice contexts.

The key idea is how a storage element captures and holds data when the clock changes. A D-type latch is designed to latch the D input and store that value at the moment the clock transitions, and then retain it until the next transition. That behavior makes it the element that records the D value at clock events, which is why it’s the best choice in this context. In contrast, a NOR or OR gate is purely combinational and does not store state, so they cannot hold the D input over time. The flip-flop also stores data on a clock edge, but the question’s phrasing is typically associated with the latch’s behavior in many practice contexts.