ITT430 – Microprocessor
Assignment 2a Topic 3
Name: NURUL AIN BINTI AMIR
Student ID: 2018683334
Group: M3CS2454A
/35 marks
Answer ALL Questions:
TOPIC 3
1. What tells a computer what to do and where to get data? (1m)

Program and microprocessor
2. What is a source code? (2m)

Source code is the set of instructions and statements written by a programmer
using a computer programming language. This code is later translated into
machine language by a compiler.
3. What is the function of an assembler? (2m)

Convert mnemonic operation codes to their machine language equivalent.

Convert symbolic operands to their equivalent machine addresses.
4. What is an opcode? (2m)

An opcode (operation code) is a code or a number that is placed inside the
memory cell by the instruction pointer.
5. What is an operand? (2m)

an operand is a term used to describe any object that is capable of being
manipulated. For example, in "1 + 2" the "1" and "2" are the operands and the
plus symbol is the operator.
ITT430 – Microprocessor
6. List six groups of instructions in the 8088/8086 instruction set? (6m)

Data transfer instructions

Arithmetic instructions

Logic instructions

String manipulation instructions

Control transfer instructions

Processor control instructions
7. What is meant by an addressing mode? (2m)

Addressing modes are an aspect of the instructions set architecture in most
central processing unit (CPU) designs. An addressing mode specifies how to
calculate the memory address of an operands using information held in registers
and / or constants contained within the instruction or elsewhere.
8. List the addressing mode available on the 8088 (3m)

Register operand addressing mode

Immediate operand addressing mode

Memory operand addressing mode
9. Name the memory operand addressing mode. (5m)

Direct addressing mode

Register indirect addressing mode

Based addressing mode

Indexed addressing mode

Based-indexed addressing mode
ITT430 – Microprocessor
10. Use the register contents shown to answer the following question. (10m)
AX=0ACD
BX=0180
CX=0000
DX=0000
SP=FFEE
BP=0000
SI=021D
DI=1111
DS=166A
ES=146A
SS=156A
CS=136A
IP=0101
For each instruction
i)
Determine the physical address of memory operand.
ii)
Determine the memory operand addressing mode.
a) MOV AH, [BX][SI] + 1234H
i. PA = DS & 0 + BX + SI + 1234H
PA = 166A0H + 0180H + 021DH + 1234H
PA = 17C71H
ii. Based-indexed addressing mode
b) SBB DL, [0200H]
i. PA = DS & 0 + 0200H
PA = 1660AH + 0200H
PA = 168A0H
ii. Direct addressing mode
c) MOV BL, [BP] + 8954H
i. PA = DS & 0 + BP + 8954H
PA = 166A0H + 0000H + 8954H
PA = 1EFF4H
ii. Indexed register addressing mode
ITT430 – Microprocessor
d) MOV AL, [SI] + 1122H
i. PA = DS & 0 + SI + 1122H
PA = 166A0H + 021DH + 1122H
PA = 179DFH
ii. Indexed register addressing mode
e) MOV AX, [BX] [DI] + 34H
i. PA = DS & 0 + BX + DI + 34H
PA = 166A0H + 0180H + 1111H + 34H
PA = 17965H
ii. Based-indexed addressing mode