问题
What addressing mode is used in "mov cx, [bp+6]"? The processor is intel 8086. I am studying "Microprocessor and Interfacing" by Douglas V. Hall. I know its memory addressing mode. But not sure whether its based addressing mode or index addressing mode?
回答1:
[bp+6] is the based addressing mode. From the original 8086 docs:
In based addressing, the effective address is the sum of a displacement value and the content of register BX or register BP.
Indexed addressing mode is similar but with the SI or DI registers.
Basically, you have the following modes:
- Direct memory accessing like
[1234]. - Register indirect like
[bx]. - Based addressing like
4[bx]or[bp+8]. - Indexed addressing like
4[si]or[di+4]. - Based indexed addressing (combo of the previous two) such as
4[bx][si]or[bx+si+4]. - Some other inconsequential (in this context) ones like implicit, port, string, relative.
来源：https://stackoverflow.com/questions/13928834/what-addressing-mode-is-used-in-mov-cx-bp6