Indexed Addressing Mode
- Indexed addressing mode is widely used in accessing data elements of look-up table entries located in the program ROM space of the 8051.
- Is used when there is a need to retrieve data from a lookup table located in the program ROM
- DPTR is used to hold base address of table and accumulator is used to hold the index
- Sum of DPTR and Accumulator forms the effective address for JMP or MOVC instruction
- Jump tables or look-up tables are easily created using indexed addressing
- 8051 has 64K bytes of code space, MOVC instruction to access a portion of this 64K-byte code space as data memory space
- Example: MOV A, #08H
MOV DPTR, #1F00H
MOVC A, @A+DPTR
Related topics:
8051 Addressing Modes | 8051 Register Addressing Mode | 8051 Direct Addressing Mode | 8051 Indirect Addressing Mode | 8051 Immediate Addressing Mode | 8051 Relative Addressing Mode | 8051 Absolute Addressing Mode | 8051 Long Addressing Mode | 8051 External Addressing Mode
List of topics: 8051
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