Bidirectional shift registers — movement of data: Evaluate the statement: “Bidirectional shift registers can shift data either to the right or to the left under control.”

Introduction / Context:Shift registers move data through flip-flop stages on clock edges. Some applications require shifting in both directions—right or left—for operations like arithmetic shifts, data alignment, and bidirectional serial interfaces. This item asks whether bidirectional devices can indeed shift either way.

Given Data / Assumptions:

• Bidirectional shift registers include a direction control input.
• On each clock, data moves one stage according to the direction selection.
• Devices may also support parallel load and serial I/O.

Concept / Approach:With an explicit direction control, the internal multiplexing routes the proper neighbor stage to each flip-flop’s input. Thus, asserting “left” moves bits toward higher-order positions while “right” moves them toward lower-order positions. The capability is explicitly designed and documented for bidirectional parts.

Step-by-Step Solution:

Verification / Alternative check:Datasheets for common bidirectional registers (for example, 74xx194/195 family) show mode tables with left/right shift options selected via control inputs.

Why Other Options Are Wrong:

Common Pitfalls:Forgetting to provide valid serial data on the incoming side when shifting; not meeting setup/hold for the direction control relative to the clock.

Final Answer:Correct