Difference between revisions of "MPLab1 Addition"

Revision as of 22:55, 17 September 2023

 .model small 
 .stack 100H

Define your data in the data section ( here you can define various data items: variables, constants, strings, arrays

data1 dd 00H

num1 db 10,13,"Enter the first number: $" num2 db 10,13,"Enter the second number: $" sum db 10,13,"The sum is :$"

Firstly lexical analyzer creates a program lex.l in the Lex language. Then Lex compiler runs the lex.l program and produces a C program lex.yy.c.
Finally C compiler runs the lex.yy.c program and produces an object program a.out.
a.out is lexical analyzer that transforms an input stream into a sequence of tokens.

A Lex program is separated into three sections by %% delimiters. The format of Lex source is as follows:

{ definitions }
%%

{ rules }

%%
{ user subroutines }

Here

Definitions include declarations of constant, variable and regular definitions.
Rules define the statement of form p1 {action1} p2 {action2}....pn {action}. Where pi describes the regular expression and action1 describes the actions what action the lexical analyzer should take when pattern pi matches a lexeme.
User subroutines are auxiliary procedures needed by the actions. The subroutine can be loaded with the lexical analyzer and compiled separately.

@@ Line 2: / Line 2: @@
 * Specify the size for code, data, and stack segments
   ''' .model small <br> .stack 100H '''
-* The lexical analyzer is a program that transforms an input stream into a sequence of tokens.
+* Define your data in the data section ( here you can define various data items: '''variables, constants, strings, arrays'''
-* It reads the input stream and produces the source code as output through implementing the lexical analyzer in the C program.<sup>[2]</sup>
+ '''data1 dd 00H
+num1 db 10,13,"Enter the first number: $"
+num2 db 10,13,"Enter the second number: $"
+sum db 10,13,"The sum is :$" '''
 ==The function of Lex is as follows:==