The hard way: Download the processor manuals and code the opcode and operands by hand
The easy way: Use an assembler program. The instructions are slightly different for each program, so try reading the manuals.
An opcode is an instruction. An operand is information used by the opcode. Not all opcodes require operands.
op code is used as the value of instruction . And operand is address location where the instruction can meet.
mov H , L mov is opcode H L are operands
3 for opcode fetch, 1 for opcode decode, 3 for operand fetch, and 3 for opcode store, for a total of 10, not including wait states.
An opcode is a single instruction in assembly language. An operand is the data it does something with.For example, in "MOV r0, #0C", MOV is the opcode ("move this value into this register"), while r0 (register 0) and #0C (the number 12) are operands.
An opcode (operation code) is a part of an instruction in machine language that specifies the operation to be performed, such as addition, subtraction, or data movement. The operand, on the other hand, is the part of the instruction that provides the necessary data or addresses required for the operation, indicating the target of the operation or the data to be manipulated. Together, the opcode and operand define the specific action and the data involved in machine-level programming.
The 8086 microprocessor differentiates between an opcode and an operand primarily through the instruction format, where the opcode is always specified first, followed by the operands. The opcode indicates the operation to be performed, while the operands represent the data or addresses on which the operation will act. The instruction's length is variable, and the processor uses specific bits in the instruction to determine the types and sizes of operands, allowing it to interpret the instruction correctly. Additionally, the opcode itself can include information about the addressing mode, further aiding in the distinction between opcodes and operands.
Each mnemonic maps directly to a machine instruction code, known as an opcode. Some mnemonics map to more than one opcode, however the instruction's operand types will determine which specific opcode will be generated.
Every instruction contains to parts: operation code[opcode],and operand. The first part of an instruction which specifies the task to be performed by the computer is called opcode. The second part of the instruction is the data to be operated on.,and it is called operand. The operand[or data]given in the instruction may be in various forms such as 8-bit or 16-bit data, 8-bit or 16-bit address, internal register or a register or memory location.
Immediate addressing mode is when one of the operands is "immediately" located after the opcode. It is more correct to say that the operand is part of the instruction.
Immediate addressing mode is when one of the operands is "immediately" located after the opcode. It is more correct to say that the operand is part of the instruction.
#include#include#includevoid main(){char opcode[10],operand[10],label[10],code[10][10],ch;char mnemonic[10][10]={"START","LDA","STA","LDCH","STCH","END"};int locctr,start,len,i=0,j=0;FILE *fp1,*fp2,*fp3;clrscr();fp1=fopen("INPUT.DAT","r");fp2=fopen("SYMTAB.DAT","w");fp3=fopen("OUT.DAT","w");fscanf(fp1,"%s%s%s",label,opcode,operand);if(strcmp(opcode,"START")==0){start=atoi(operand);locctr=start;fprintf(fp3,"%s\t%s\t%s\n",label,opcode,operand);fscanf(fp1,"%s%s%s",label,opcode,operand);}elselocctr=0;while(strcmp(opcode,"END")!=0){fprintf(fp3,"%d",locctr);if(strcmp(label,"**")!=0)fprintf(fp2,"%s\t%d\n",label,locctr);strcpy(code[i],mnemonic[j]);while(strcmp(mnemonic[j],"END")!=0){if(strcmp(opcode,mnemonic[j])==0){locctr+=3;break;}strcpy(code[i],mnemonic[j]);j++;}if(strcmp(opcode,"WORD")==0)locctr+=3;else if(strcmp(opcode,"RESW")==0)locctr+=(3*(atoi(operand)));else if(strcmp(opcode,"RESB")==0)locctr+=(atoi(operand));else if(strcmp(opcode,"BYTE")==0)++locctr;fprintf(fp3,"\t%s\t%s\t%s\n",label,opcode,operand);fscanf(fp1,"%s%s%s",label,opcode,operand);}fprintf(fp3,"%d\t%s\t%s\t%s\n",locctr,label,opcode,operand);fcloseall();printf("\n\nThe contents of Input Table :\n\n");fp1=fopen("INPUT.DAT","r");ch=fgetc(fp1);while(ch!=EOF){printf("%c",ch);ch=fgetc(fp1);}printf("\n\nThe contents of Output Table :\n\n\t");fp3=fopen("OUT.DAT","r");ch=fgetc(fp3);while(ch!=EOF){printf("%c",ch);ch=fgetc(fp3);}len=locctr-start;printf("\nThe length of the program is %d.\n\n",len);printf("\n\nThe contents of Symbol Table :\n\n");fp2=fopen("SYMTAB.DAT","r");ch=fgetc(fp2);while(ch!=EOF){printf("%c",ch);ch=fgetc(fp2);}fcloseall();getch();}INPUT FILE:INPUT.DAT** START 2000** LDA FIVE** STA ALPHA** LDCH CHARZ** STCH C1ALPHA RESW 1FIVE WORD 5CHARZ BYTE C'Z'C1 RESB 1** END **-Fabianski Benjamin