Shift-register feature sets: Evaluate the claim that practically every possible load, shift, and conversion operation is available in a single shift-register IC.

Difficulty: Easy

Correct Answer: Incorrect

Explanation:


Introduction / Context:
Shift registers come in many variants: serial-in serial-out, serial-in parallel-out, parallel-in serial-out, universal, bidirectional, with or without asynchronous load, and different enable schemes. Datasheets specify a finite feature set per device. No single IC covers literally every operation and conversion possibility without external logic.


Given Data / Assumptions:

  • Diverse part numbers across logic families and vendors.
  • Common operations: parallel load, serial shift left/right, hold, clear, bidirectional control.
  • Conversions: SISO, SIPO, PISO, PIPO realized by different or universal devices.


Concept / Approach:
Universal shift registers provide broad capabilities (serial and parallel I/O, bidirectional shifting) but still have defined limits. Some conversions may require multiple packages or extra gating (e.g., width expansion, specialized recirculation, Gray/Binary conversions). Therefore the phrase 'practically every possible' is marketing-sounding and not technically accurate as a universal truth.


Step-by-Step Solution:
1) Identify the operations you need (e.g., PISO plus bidirectional shift and synchronous clear).2) Check the target device function table; missing modes mean additional logic or a different part is required.3) For uncommon conversions, compose multiple devices or add small glue logic.4) Conclude that one chip cannot guarantee 'every possible' operation.


Verification / Alternative check:
Compare several universal shift-register datasheets; features vary, and some modes are absent or mutually exclusive.


Why Other Options Are Wrong:
“Correct” exaggerates device capabilities. “Only true for universal” remains too broad. “True with glue logic” changes the premise to a multi-chip solution.


Common Pitfalls:
Assuming a 'universal' label equals unlimited capability; not reading function tables closely.


Final Answer:
Incorrect

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