8051 register moves — which instruction copies the contents of the Accumulator into register R6? Select the correct MOV form that implements R6 ← A.

Introduction / Context:
MOV on the 8051 supports many addressing forms, but register names and operand order must follow the ISA grammar. Moving data from A to a register requires the correct destination syntax.

Given Data / Assumptions:

• Source: Accumulator A
• Destination: register R6 (in the current bank)
• Goal: R6 ← A

Concept / Approach:
For register-to-register moves involving A, the allowed form is MOV Rn, A or MOV A, Rn. Here we want R6 to receive A, so MOV R6, A is the right direction. Tokens like 6R are not valid, and @R6 indicates indirect memory via a register pointer, which is not supported (only @R0 or @R1 are legal indirect registers).

Step-by-Step Solution:

Verification / Alternative check:
Instruction tables show MOV Rn, A as a single-byte opcode when Rn ∈ {R0…R7}.

Why Other Options Are Wrong:

• MOV 6R, A and MOV A, 6R: invalid register tokens.
• MOV A, R6: opposite direction (A ← R6).
• MOV @R6, A: @R6 is not a valid indirect register (only R0/R1).

Common Pitfalls:

• Writing mnemonic-like tokens (6R) instead of proper register names (R6).

Final Answer:
MOV R6, A