Universal shift register What do we call a shift register that supports parallel loading, bidirectional serial loading, and internal shifting features?

Introduction / Context:
Shift registers range from simple serial-in/serial-out devices to fully flexible units that can load in parallel, shift left or right, and accept serial data from either side. The industry uses a specific name for the most flexible category, frequently found in timing, communication, and data format conversion tasks.

Given Data / Assumptions:

• Device supports parallel input (loads multiple bits simultaneously).
• Supports bidirectional serial loading (left or right).
• Supports internal shifting (controlled by clock and mode signals).

Concept / Approach:
A “universal shift register” is designed to perform parallel load, shift-left, shift-right, and hold operations under mode control. It can ingest serial data from either end, making it useful for interfacing between serial and parallel buses and for bit manipulation tasks.

Step-by-Step Solution:
Recognize feature set: parallel load + bidirectional serial + shift = universal capability.Match to standard terminology: “universal shift register.”Therefore, the correct name is Universal shift register.

Verification / Alternative check:
Common parts such as the 74HC194/74HC195 are expressly identified as universal shift registers in datasheets, supporting load and bidirectional shifting via mode inputs S1/S0 and a clock.

Why Other Options Are Wrong:

• End-around: Usually refers to connecting serial output back to serial input to form ring/Johnson sequences, not parallel load capability.
• Tristate: Describes output driving capability, not shift functionality.
• Conversion register: Not a standard term for this feature set.

Common Pitfalls:

• Confusing “bidirectional” with “tristate” outputs.
• Assuming “universal” means any IC with both serial and parallel paths; true universal devices provide left/right shifting under control.

Final Answer:
Universal shift register