RET

RET (Return) Instruction

Definition

The "RET" (Return) instruction is a fundamental component of assembly language programming used to return control from a subroutine to the calling code. When a subroutine completes its execution, it employs the "RET" instruction to transfer control back to the point in the main program or calling code from which the subroutine was initially invoked.

Usage

The "RET" instruction is vital for maintaining the flow of a program and ensuring that control is appropriately transferred after the completion of a subroutine. Here are key points outlining the usage of the "RET" instruction:

1. Subroutine Termination:

   RET

   The "RET" instruction is placed at the end of a subroutine to indicate its conclusion. When encountered during program execution, "RET" initiates the process of returning control to the calling code.

2. Return to Calling Code: The primary purpose of the "RET" instruction is to facilitate the return to the main program or the specific point in the code where the subroutine was originally called. This allows the main program to resume execution after the subroutine's task is completed.

3. Continuation of Execution:

   CALL .subroutine
   ...
   RET

   In the context of a program, the "CALL" instruction is used to invoke a subroutine, and "RET" is placed after the subroutine's code block. This sequence ensures the proper continuation of execution in the main program.