AHDL basics — In Altera/Intel AHDL, the SUBDESIGN header defines a block’s interface (its inputs and outputs). Decide whether this description of the SUBDESIGN section's role is accurate.
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ACorrect
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BIncorrect
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COnly true in VHDL, not AHDL
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DDepends on device family
Answer
Correct Answer: Correct
Explanation
Introduction / Context: Various HDL dialects introduce different keywords for defining a module's interface. In AHDL (a vendor-specific language historically used with Altera tools), the SUBDESIGN construct defines a design block and declares its ports (inputs/outputs) at the header level.Given Data / Assumptions:
- Language context: AHDL, not VHDL or Verilog.
- SUBDESIGN header includes port lists (I/O).
- Functional details follow in the body after the interface declaration.
Concept / Approach: In AHDL syntax, the top line begins with SUBDESIGN name (port declarations); this is conceptually similar to a module header in Verilog or an entity in VHDL. Therefore, stating that the SUBDESIGN section defines inputs/outputs of the logic circuit block is correct.Step-by-Step Solution:
Identify the language keyword: SUBDESIGN.Recognize that the port list occurs with the SUBDESIGN header.Confirm: interface (I/O) is defined there; detailed logic follows.Verification / Alternative check:
Compare with standard templates from legacy Quartus/Max+Plus II documentation; ports live in the header, matching the description.Why Other Options Are Wrong:
Incorrect / Depends on device family: The syntax behavior is language-defined, not device-specific.Only true in VHDL: VHDL uses entity for ports, not SUBDESIGN.Common Pitfalls:
Confusing AHDL keywords with VHDL/Verilog modules and mixing examples across languages.Assuming device family alters language grammar; it does not.Final Answer:
Correct