Parallel-loaded 4-bit shift register behavior A 4-bit shift register that initially receives 4 bits of parallel data will, on each clock pulse, shift in which direction and by how many positions?

Introduction / Context:
Shift registers can be configured for serial-in/serial-out, parallel-in/serial-out, and other modes. After a parallel load, each subsequent clock typically shifts the stored bits uniformly in a predefined direction by one stage. This question tests your grasp of the basic shift behavior per clock edge.

Given Data / Assumptions:

• A 4-bit register can load 4 bits simultaneously (parallel load).
• After loading, the register shifts with each clock.
• No special “shift by N>1” hardware is implied.

Concept / Approach:
Standard shift registers move data one stage per clock to the left or right, depending on the design (e.g., right-shift for SIPO like 74HC164, or left-shift variants). Unless explicitly stated otherwise, “shift” means one position per active clock edge in the specified direction. Many textbook examples assume right shift for serial-out from Q0 or Q3, but direction is device-dependent; here the common interpretation is right by one.

Step-by-Step Solution:
Parallel load places bits simultaneously into all four stages.On each clock, all bits step to the next stage.Thus, the register shifts right by one position per clock in the typical configuration.

Verification / Alternative check:
Examine timing diagrams for common ICs (e.g., 74HC194/195 universal shift registers): they show one-position shifts per clock edge when in shift mode.

Why Other Options Are Wrong:

• Left by one: Possible for left-shift devices, but not assumed here; question implies the standard right-shift convention.
• Right by two / Left by three: Multi-position shifting per clock is nonstandard without special logic.

Common Pitfalls:

• Assuming multi-bit jumps per clock; normal devices shift one stage per edge.
• Ignoring that actual direction depends on IC; always check the datasheet mode pins.

Final Answer:
Right by one position per clock