University:
Mt. San Antonio College
Course:
ELEC 74 | Microprocessor Systems
Academic year:

2024
Views:

286

Pages:

2
Author:

Dipin K.

Modular Programming in 8086 Assembly Modular programming is a prominent software development technique characterized by the dissection of a substantial program into more manageable units, termed as modules. These modules, commonly denoted as procedures or subroutines, are capable of autonomous development, rigorous testing, and repeated utilization. This method significantly amplifies code comprehensibility, sustainability, and recyclability. Benefits of Modular Programming in 8086 The benefits of modular programming are manifold. Firstly, it enhances the readability of code by allowing each module to concentrate on a specific task, thus contributing to a clearer overall program structure. Secondly, it improves maintainability by facilitating changes or bug fixes within individual modules without impacting the entire program, thereby minimizing the risk of introducing new errors. Furthermore, modular programming increases reusability as well-designed modules can be employed in other projects, ultimately saving valuable development time and effort. Additionally, it simplifies testing by enabling independent testing of each module, thus streamlining the process of error identification and rectification. Lastly, modular programming fosters improved collaboration by facilitating concurrent work on different modules by multiple developers, thereby accelerating the development process. Implementing Modular Programming in 8086 In 8086 assembly language, modules are commonly created as procedures. A procedure is a section of code that can be invoked from other sections of the program. When a procedure is invoked, the program's flow of control moves to the start of the procedure, and upon completion of the procedure, the control returns to the location from which it was called. Basic Structure of a Procedure: Code snippet PROCEDURE_NAME PROC NEAR ; Procedure code here RET PROCEDURE_NAME ENDP  PROCEDURE_NAME: The name of the procedure.    PROC NEAR: Defines the procedure as near (within the same code segment). RET: Returns control to the calling point. ENDP: Ends the procedure definition.  Calling a Procedure: To call a procedure, use the CALL instruction followed by the procedure's name. For example: Code snippet CALL PROCEDURE_NAME Passing Parameters: Procedures can accept parameters to perform different actions based on the input data. There are two standard methods for passing parameters: 1. Using Registers: Pass parameters through registers like AX, BX, CX, DX, etc. 2. Using the Stack: Push parameters onto the stack before calling the procedure and pop them off after the procedure returns. Example: Code snippet ; Procedure to add two numbers ADD_NUMBERS PROC NEAR MOV AX, BX ; Add the values in BX and CX ADD AX, CX RET ADD_NUMBERS ENDP ; Main program MOV BX, 10 MOV CX, 20 CALL ADD_NUMBERS ; The result will be in AX