Assignment 2: MARIE & ISA Value: 15% Task 1. A digital computer has a memory unit with 16 bits per word. The instruction set consists of 122 different operations. All instructions have an operation code part (opcode) and an address part (allowing for only one address). Each instruction is stored in one word of memory. [4 marks] a) How many bits are needed for the opcode? b) How many bits are left for the address part of the instruction? c) What is the maximum allowable size for memory? d) What is the largest unsigned binary number that can be accommodated in one word of memory? 2. Consider the MARIE program below. [5 marks] a) List the hexadecimal code for each instruction. [1.5 marks] b) Draw the symbol table. [1.5 marks] c) What is the value stored in the AC when the program terminates? [2 marks] Hex Addr Label Instruction 100 Start, Load A 101 Add B 102 Store Temp 103 Load C 104 Add D 105 Add Temp 106 Store F 107 Output 108 HALT 109 A, DEC 5 10A B, DEC 3 10B C, DEC 4 10C D, DEC 13 10D E, DEC 3 10E Temp, HEX 00FD 10F F, HEX 00FE 3. Write code to implement the expression F = (A+B) /(C*D*E) on 2-, 1- and 0-address machines. [6 marks] Online submission via Turnitin is required for this assignment. Rationale This assessment task covers topics on CPU operation and Instruction Set Architecture, and has been designed to ensure that you are engaging with the subject content on a regular basis. More specifically it seeks to assess your ability to: • be able to define and appropriately use computer systems terminologies; • be able to describe the essential elements of computer organisation and discuss how the elements function; • be able to describe the basic instruction set architecture of a simple computer; • be able to discuss the general trends in computing technologies including examples of leading edge developments. Marking criteria The following marking criteria will be used to mark this assignment: Questions Fail (<50%) Pass (50% - 64%) Credit (65% - 74%) Distinction (75% - 84%) High Distinction (>84%) Question 1 &2 Incorrect answer with no demonstration of understanding the topic. Student demonstrate the understanding, however the calculations are incorrect. Answers are correct, omission of few calculations. Answers are correct, but the steps have minor kistakes. Answers are correct and clearly show the calculations Question 3 Answers are incorrect Any one address is fully correct and the remaining 2 address are not correct Any 2 addresses are fully correct and the remaining 1 address is not correct All the three addresses are correct, but has some minor steps mistakes Total marks Answers are fully correct with the steps.