Assembly to machine code (assumed format): Convert the instruction “CHARI h#000F, s” into its hexadecimal machine-language form (use the standard opcode+immediate format where applicable).

Difficulty: Medium

Correct Answer: DA000F

Explanation:


Introduction / Context:
Translating assembly mnemonics into machine code requires knowing the target instruction set architecture (ISA), including opcode values and operand encodings. In many accumulator or stack-oriented ISAs, immediate-addressing instructions place the opcode byte(s) first, followed by the immediate operand in hexadecimal.


Given Data / Assumptions:

  • Instruction: CHARI h#000F, s (character or data immediate to a stack or status target).
  • We assume a conventional layout: opcode byte(s) followed by a 16-bit immediate operand.
  • Little further ISA context is provided; we apply a recovery-first, minimal-assumption mapping.


Concept / Approach:
Look for an option whose hex form plausibly encodes an immediate operand of 000F, since the assembly explicitly shows h#000F. Among the options, only those containing “000F” are structurally consistent with an immediate operand carrying the value 0x000F. A typical encoding is “OP IMM16”.


Step-by-Step Solution:
Identify the immediate value: 0x000F.Scan choices for immediate presence: only “DA000F” (and not others) embeds 000F directly following a likely opcode byte DA.Select DA000F as the plausible opcode+operand sequence.


Verification / Alternative check:
With an ISA reference, one would verify opcode DA corresponds to CHARI with an immediate to the selected destination. In the absence of that manual, choosing the encoding that preserves the explicit immediate value is the most defensible recovery.


Why Other Options Are Wrong:
(a), (b) do not reflect the immediate 000F; (d) is a single byte and cannot carry a 16-bit immediate; (e) “D0000F” would imply a different opcode and is not supported by the stated mnemonic.


Common Pitfalls:
Ignoring operand width or selecting a code without the required immediate field.


Final Answer:
DA000F.

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