Segmentation
There are some special combinations of segment registers and general registers that point to important addresses:
| Register Pair | Full Name | Description |
|---|---|---|
CS:IP | Code Segment : Instruction Pointer | Points to the address where the processor will fetch the next byte of code. |
SS:SP | Stack Segment : Stack Pointer | Points to the address of the top of the stack, i.e., the most recently pushed byte. |
SS:BP | Stack Segment : Base Pointer | Points to the address of the top of the stack frame, i.e., the base of the data area in the call stack for the currently active subprogram. |
DS:SI | Data Segment : Source Index | Often used to point to string data that is about to be copied to ES:DI. |
ES:DI | Extra Segment : Destination Index | Typically used to point to the destination for a string copy, as mentioned above. |