Implement pass-II of a two-pass assembler for 8-bit microprocessor/ pseudo-machine. The output of assignment-1 (intermediate file and symbol table) should be input for this assignment.

SOFTWARE LABORATORY

We need ic.txt , st.txt , lt.txt for this program generated by assembler pass I

You con watch http://www.engineersvision.com/2013/01/design-suitable-data-structures-and.html

put that ic.txt , st.txt , lt.txt in same folder where you want your assembler pass 2 program .

Code for you :

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

struct mottab

{

    char name[8];

    int class;

    char info[4];

};

struct symtab

{

    char sym[8];

    int address;

    int len;

}st[20];

struct littab

{

    int lit;

    int address;

}lt[20];

int pt[5]={0};

struct ictab

{

    int lc;

    int class1,no1;

    int class2,no2;

    int class3,no3;

}ic[50];

int ipt=0,ilt=0,ist=0,iic=0;

static struct mottab mot[30]={{"STOP",1,"00"},{"ADD",1,"01"},{"SUB",1,"02"},{"MULT",1,"03"},{"MOVEM",1,"04"},{"MOVER",1,"05"},{"COMP",1,"06"},{"BC",1,"07"},{"DIV",1,"08"},{"READ",1,"09"},{"PRINT",1,"10"},{"START",3,"01"},{"END",3,"02"},{"ORIGIN",3,"03"},{"EQU",3,"04"},{"LTORG",3,"05"},{"DS",2,"01"},{"DC",2,"02"},{"AREG",4,"01"},{"BREG",4,"02"},{"CREG",4,"03"},{"EQ",5,"01"},{"LT",5,"02"},{"GT",5,"03"},{"LE",5,"04"},{"GE",5,"05"},{"NE",5,"06"},{"ANY",5,"07"}};

int main()

{

    FILE * fp;

    char buffer[60],s1[10],s2[10],s3[10],s4[10],s5[8],s6[8],s7[8];

    int i,lc;

    fp=fopen("st.txt","r");

   

    while(fgets(buffer,40,fp)!=0)

    {

        sscanf(buffer,"%s%s%s",s1,s2,s3);

        strcpy(st[ist].sym,s1);

        st[ist].address=atoi(s2);

        st[ist++].len=atoi(s3);

    }

    fclose(fp);

    fp=fopen("lt.txt","r");

    while(fgets(buffer,20,fp)!=0)

    {

        sscanf(buffer,"%s%s",s1,s2);

        lt[ilt].lit=atoi(s1);

        lt[ilt++].address=atoi(s2);

    }

    fclose(fp);

    fp=fopen("ic.txt","r");

    while(fgets(buffer,40,fp)!=0)

    {

        sscanf(buffer,"%s%s%s%s%s%s%s",s1,s2,s3,s4,s5,s6,s7);

        ic[iic].lc=atoi(s1);

        ic[iic].no1=atoi(s2);

        ic[iic].class1=atoi(s3);

        ic[iic].no2=atoi(s4);

        ic[iic].class2=atoi(s5);

        ic[iic].no3=atoi(s6);

        ic[iic++].class3=atoi(s7);

    }

    fclose(fp);

    printf("\n\t**************Target Code ******************");

    for(i=0;i<iic;i++)

    {

        if((ic[i].class1==3 && ic[i].no1==1) || (ic[i].class1==3 && ic[i].no1==3) )    //start or origin

        {

            lc = ic[i].no2;

            continue;

        }

        if(ic[i].class1==1)    //ie imperative statement

        {

            printf("\n\t\t %d )\t %d",ic[i].lc,ic[i].no1);

            if(ic[i].class2==4)

                printf("\t%d",ic[i].no2);

            else

                printf("\t%d",st[ic[i].no2].address);

            if(ic[i].class3==4)

                printf("\t%d",ic[i].no3);

            else

                if(ic[i].class3!=0)

                    if(ic[i].class3==7)

                        printf("\t%d",st[ic[i].no3].address);

                    else

                        printf("\t%d",lt[ic[i].no3].address);

        }

        else

        {

            printf("\n\t\t %d )\t 0 \t00 \t00",ic[i].lc);

        }

    }

}

run above programm as :

root@prashant-HP-ENVY-4-Notebook-PC:~/SPOS Programs/ass pass2# gcc ap2.c

root@prashant-HP-ENVY-4-Notebook-PC:~/SPOS Programs/ass pass2# ./a.out

    **************Target Code ******************

         200 )     5    1    208

         201 )     5    2    217

         202 )     5    3    216

         203 )     5    2    220

         204 )     5    3    221

         205 )     1    2    1

         206 )     2    2    3

         207 )     4    209    2

         208 )     0     00     00

         209 )     0     00     00

         214 )     10    209

         215 )     0     00     00

         218 )     0     00     00

         219 )     0     00     00