SIPO timing — keeping parallel output data accurate To keep output data accurate, 4-bit serial-in, parallel-out (SIPO) shift registers typically employ which control line?

Introduction / Context:
Serial-in, parallel-out (SIPO) shift registers receive bits serially but often need to present a stable 4-bit word to downstream logic. Designers use a separate output latch with a strobe (latch enable) to avoid glitches while shifting.

Given Data / Assumptions:

• A 4-bit SIPO is shifting new bits on each clock.
• We want a clean, accurate parallel output word only when loading is complete.
• Common solution uses an internal or external latch controlled by a strobe line.

Concept / Approach:

During shifting, internal register stages change every clock. A strobe (latch enable) captures the register contents into an output latch at a defined instant, isolating downstream circuitry from intermediate transitions. This improves data integrity and timing closure.

Step-by-Step Solution:

Verification / Alternative check:

Datasheets for classic parts (e.g., 74HC595) show a shift register feeding a storage register; the storage register is updated by a RCLK/LATCH signal (strobe), ensuring accurate outputs.

Why Other Options Are Wrong:

• Divide-by-4 clock: changes frequency, not output coherency.
• Sequence generator: unrelated; generates patterns, not latching.
• Multiplexer: selects signals, does not freeze outputs.

Common Pitfalls:

• Driving loads directly from shifting stages without a latch, causing visible ripple on displays.

Final Answer:

strobe line