Summer 2005 CSE 141L Projects in Computer Architecture Lab 2 Construct Assembler Instruction Set Simulator Reports are due at the beginning of class on Tuesday July 11th In this lab you will design an Assembler and an Instruction Set Simulator ISS for the 8 bit processor architecture you developed in Lab 1 You will assemble the three programs you developed in Lab 1 using the assembler and then run the three programs on the ISS ensuring that they function correctly This lab also has a homework assignment as specified below What you will turn in for this Lab Written Report Only Summary of your ISA from Lab 1 including any changes you might have made Static and dynamic instruction count for each one of the three programs Answers to the questions below Written Report Electronic Turn in Three assembly files annotated with machine code generated by your Assembler as well as the imi files for the three programs A complete instruction trace for the three programs executing correctly on the ISS A memory dump of D Mem before and after running each one of the three programs Electronic Turn in Only Complete code for your Assembler including all header files Complete code for your ISS including all header files A makefile for compiling your Assembler and ISS Alternatively you must provide instructions on how to compile these programs Implementation of the Assembler You may write your Assembler in C C Java or as a Perl script For a description of the input assembly file see the Lab 1 project specifications Following are the requirements for the assembler Your assembler executable should be named assembler and should be able to be invoked on the command line by itself The only exceptions are Assemblers coded in Java which require the Java interpreter to accompany the executable name Your assembler should take two 2 command line arguments The first argument is the input assembly file and the second argument is the output file annotated with the machine code e g assembler mean s mean dis for c c perl programs e g java assembler mean s mean dis for java programs Before running the assembler program on your assembly code you should remove the hand generated machine code from it The machine code is the hexadecimal encoding of your assembly code This 2 digit hex code will be inserted at the beginning of each assembly instruction line in your s file to generate the corresponding dis file The assembler should generate a corresponding imi file by default e g For above command line mean imi will be generated that has only the hex machine code formatted one instruction per line The assembler should be able to parse the required fields instruction mnemonic operand s as well as the optional label and comment fields The assembler should generate the machine code as well as the program counter PC for each instruction The PC should start at 0x0 Your assembler must compile and run on ieng9 ucsd edu for credit No exceptions Implementation of the Instruction Set Simulator ISS You may write your ISS in C or Java C is OK too with suitable modifications to the instructions below You should define a class e g Proc whose members are the resources of the processor e g program counter registers instruction memory data memory etc You should define following methods loadIMem Reads a text file with hex machine code for your program and loads the instruction memory I Mem starting from location 0 loadDMem Reads a text file with data for your program and loads the data memory D Mem starting from location 0 reset Initializes the internal state of your processor e g sets PC to address 0 runLoop Executes instructions This function may take an argument for number of instructions to simulate This will enable you to advance the simulation by a suitable number of instructions including single stepping HALT instruction would stop execution of the program RunLoop needs to perform the following steps 1 Fetch Read 8 bits from I Mem at location pointed to by the current value of PC 2 Decode Analyze the fetched instruction and find opcode and other fields such as register s immediate data branch offset etc Read operand s from register s if any 3 Execute Do the ALU operation specified by the instruction D Mem may be read during this step The result of the instruction is either the output of the ALU or the data read from D Mem If the instruction is a control transfer instruction e g a conditional branch determine whether it is taken or not 4 Memory Register Writeback Write the result produced in Execute step above to the destination specified by the instruction which may be a register and or D Mem 5 Set Next PC If the instruction is not a branch or branch not taken set PC to PC 1 Otherwise set PC to the target of the branch 6 Generate instruction trace For each instruction you should print the disassembled instruction which looks exactly like an instruction in your assembly file In addition it shows the values read for the operands from the register file and the effective address in the case of memory load or store instruction You may include any additional information that may be useful for you to debug the programs 7 Go back to step 1 and continue processing until HALT instruction is encountered 2 dumpIMem Dump contents of I Mem It may take arguments for the start and end memory locations and may be used for debugging your program dumpDMem Dump contents of the D Mem It may take arguments for the start and end memory locations and may be used to inspect the contents of the data memory before during and after execution of a program main You would make an instance of your class load I Mem as well as D Mem reset the processor and go through the run loop At the end of the simulation ISS should output the dynamic instruction count for the complete program You should also dump the contents of the data memory before and after execution of the program to show that the results of the program are correct In main you must implement a command level interface that would receive input commands from the user and carry out specific functions such as advance the simulation by N instructions dump memory contents in a given range etc The following are the requireme nts for the instruction set simulator Your ISS executable should be named iss and should be able to be invoked on the command line by itself The only exception is an ISS coded in Java which requires the Java interpreter to accompany the executable name Your ISS should take three 3 command line