Why do we need to reassign sp when programming?

Reason: After the system is reset, the SP content is 07H; if it is not redefined, 07H will be the bottom of the stack, and the stacked content will be stored starting from unit 08H; if a stack with a larger depth needs to be used, set Will affect the use of working registers.

The operating environment of this tutorial: Windows 10 system, Dell G3 computer.

The stack is an area in the internal data RAM area where data is first in, last out or last in, first out. Its specific functions are two: protecting breakpoints and protecting the scene.

The stack pointer (SP) is an 8-bit register that stores the address of the storage unit pointed to by the top of the current stack. When data is stored or retrieved from the stack, the contents of the stack pointer are automatically incremented or decremented as part of the execution of stack manipulation instructions.

Why do we need to reassign SP during program design?

After the system is reset, the SP content is 07H. If it is not redefined, 07H will be the bottom of the stack, and the contents of the stack will be stored starting from unit 08H. If a stack with a larger depth is needed, it will affect the use of working registers. Therefore, the SP must be reassigned so that the stack area is set in a certain blank area in the on-chip data RAM area, and the stack depth is limited to not exceeding the on-chip RAM space.

For more related knowledge, please visit the FAQ column!

The above is the detailed content of Why do we need to reassign sp when programming?. For more information, please follow other related articles on the PHP Chinese website!