Instruction set of 8051

The instructions of 8051 Microcontroller can be classified into five different groups. These groups are like below

• Data Transfer Group

• Arithmetic Group

• Logical Group

• Program Branch Group

• Bit Processing Group

This Bit-Processing group is also known as Boolean Variable Manipulation.

Like 8085, some instruction has two operands. The first operand is the Destination, and the second operator is Source.

In the following examples, you will get some notations. The notations are like −

Rn = Any register from R0to R7
Ri = Either R0 or R1
d8 = Any 8-bit immediate data (00H to FFH)
d16 = 16-bit immediate data
a8 = 8-bit address
bit = 8-bit address of bit which is bit addressable
rel = 8-bit signed displacement. The range is -128 to 127. It is relative to the first byte of the instruction.