Indirect Addressing Mode
- This mode uses pointer to hold the effective address of the operand
- Only registers R0, R1 and DPTR can be used as pointer register
- R0 and R1 can hold 8-bit address
- DPTR can hold 16-bit address
- DPTR is useful in accessing operands in external memory
- Operand address is determined during run-time
- Make data accessing dynamic
- Indirect addressing is represented by a @ before R0 or R1 or DPTR
- Indirect addressing always refers to 128 bytes (00H – 7FH) of Internal RAM
- Example: MOV @R0, A
The above instruction store the content of accumulator in memory location pointed by R0
MOV A, @DPTR
The above instruction transfer the content from memory location pointed by DPTR in to accumulator
Related topics:
8051 Addressing Modes | 8051 Register Addressing Mode | 8051 Direct Addressing Mode | 8051 Immediate Addressing Mode | 8051 Relative Addressing Mode | 8051 Absolute Addressing Mode | 8051 Long Addressing Mode | 8051 Indexed Addressing Mode | 8051 External Addressing Mode
List of topics: 8051
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