The 8051 instruction, MOV C, 80H copies:
(A) Content of RAM location 80H to C register
(B) Content of RAM location 80H to Code memory
(C) Content of PORT 0 to C register
(D) Status of p 0.0 pin of PORT 0 to carry flag
Answer (2)
The question is about an instruction used in the 8051 microcontroller, which is a popular microcontroller in engineering and computer science. The instruction MOV C, 80H involves the Carry flag and the bit-addressable memory of the 8051.
In the 8051 architecture:
The instruction MOV C, bit is used to move the value of a specific bit in the bit-addressable memory space to the Carry flag.
Address 80H is part of the SFR (Special Function Register) area, specifically it is the location for the P0 register (Port 0).
Thus, the instruction MOV C, 80H moves the value of the least significant bit of the P0 port, specifically P0.0, to the Carry flag.
Therefore, the correct choice is:
(D) Status of p 0.0 pin of PORT 0 to carry flag.
This means that the current state (high or low) of the first pin (p0.0) of Port 0 is transferred to the Carry flag in the processor’s status register. The Carry flag is a single bit in the processor that is often used for bit-level operations and decision-making in the code.
The instruction 'MOV C, 80H' in the 8051 microcontroller takes the status of the P0.0 pin and transfers it to the Carry flag. The correct answer choice is (D), as it describes this operation accurately. This allows the microcontroller to use the state of the Carry flag in future computations.
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