Depending on the register (reg = RRR ), the contents of the specified register will be exchanged with the accumulator. This operation is having one operand which is specified in a register.

ASC Adjust for addition AAA                   00110111                  

Here the operand to this instruction is implicit and it take the contents of register AL .

b) Register to Register : This format is 2 bytes long. The first byte of the code specifies the operation code and the width of the operand specifies by w bit. The second byte of the opcode shows the register operands and RIM field.

       

The register represented by the REG field is one of the operands. The RIM field specifies another register or memory location, ie., the other operand. The register specified by REG is a source operand if , else it is a destination operand.