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4 operand address addressing, 1 direct addressing – NEC switch User Manual

Page 51

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CHAPTER 3 CPU ARCHITECTURE

User’s Manual U12978EJ3V0UD

51

3.4 Operand Address Addressing

The following methods are available to specify the register and memory (addressing) to undergo manipulation

during instruction execution.

3.4.1 Direct addressing

[Function]

The memory indicated by immediate data in an instruction word is directly addressed.

[Operand format]

Identifier

Description

addr16

Label or 16-bit immediate data

[Description example]

MOV A, !FE00H; When setting !addr16 to FE00H

Instruction code

0

0

1

0

1

0

0

1

Opcode

0

0

0

0

0

0

0

0

1

1

1

1

1

1

1

0

00H

FEH

[Illustration]

7

0

Opcode

addr16 (Low)

addr16 (High)

Memory