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Which of the following addressing mode is not usable in the XCH instruction of the 8051 microcontrollers?

Which of the following addressing mode is not usable in the XCH instruction of the 8051 microcontrollers? Correct Answer Immediate Addressing

Concept:

The different modes are listed below with the syntax.

Addressing Mode

Function

Syntax

Remarks

Direct

The source and destination can be either a register or a RAM location but both can’t be the same.

MOV A, R0

Direct addressing places the value 55H in the accumulator.

Indirect

Accesses the data at the address placed inside a register. We use the (@) symbol for this purpose.

MOV R0, #55H

MOV A, @ R0

Indirect addressing places the value 55H in R0

Places the data stored in the memory location 55H in the accumulator.

Register

The source and destination both are registers.

MOV A, R0

Move the contents from R0 to the register.

Immediate

Data is directly put into registers.

MOV A, # 50H

 

Move the data directly to the accumulator.

 

Explanation:

The XCH operation and the possible modes are listed below the table.

Instructions

Opcode

Bytes

Cycles

Flags

XCH A, @R0

0xC6

1

1

None

XCH A, @ R1

0xC7

1

1

None

XCH A, R0

0xC8

1

1

None

XCH A, R1

0xC9

1

1

None

XCH A, R2

0xCA

1

1

None

XCH A, R3

0xCB

1

1

None

XCH A, R4

0xCC

1

1

None

XCH A, R5

0xCD

1

1

None

XCH A, R6

0xCE

1

1

None

XCH A, R7

0xCF

1

1

None

XCH A, iram addr

0xC5

2

1

None

 

Conclusion:

Immediate addressing mode is not usable in XCH instruction of 8051 microcontroller

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