Architecture of the ARM microprocessor_Project 7 Solution

Computer Project #7
Assignment Overview
This assignment develops familiarity with the instruction set architectureof the ARMmicroprocessor, as well as the format of its machine languageinstructions.
It is worth40 points (4% of course grade).
The deliverablesfor this assignmentarethe following files:
proj07.makefile –themakefile which produces "proj07" proj07.support.c –the source code for yoursupportmodule proj07.driver.c –the source codefor your driver module
Assignment Specifications
An assembler is a program which converts assembly language statements into machine language instructions; a disassembler is a program which converts machine language instructions into assembly language statements.
1. You will develop asupportmodule which could be used by a disassembler for ARM machine language instructions. The interface to the support module is the following C function:
void decode( unsigned int, char[] );
Thefirstargument is the bit pattern for an ARM machine language instruction.
The second argument is the address of an array where function “decode” will store a null-terminated character stringrepresenting themachine language instruction.
Function “decode”will accept a 32-bit unsigned integer value and attempt to disassemble it. If the bit pattern corresponds to an ARM machine language instruction from the set defined below, function “decode” will produce a human-readable representation of the instructionand store it in the array (the second argument). Otherwise, it will produce an appropriate warning and store it in the array.
The support module will consist of function “decode” and any additional helper functions which you choose to implement. The support module will not perform any input or output operations. For example, the functions in the support module willnotcall function “scanf” or function “printf”.
2. You will develop a driver module totest your implementation of thesupportmodule. The driver module will consist of function "main" and anyadditional helper functions which you choose to implement. All output will be appropriately labeled.
Your driver module may not be written as an interactiveprogram, where the user supplies input inresponse to prompts. Instead,your test cases will be included in the source code as literal constants.
Assignment Notes
1. Yourdrivermodule and yoursupportmodule must be in separate source code files.
2. Your source code must be translated by"gcc", which is a C compiler and accepts C source statements.
3. You must supply a "makefile" (named"proj07.makefile"), andthat makefile must produce an executable program named "proj07".
4. Your support module will recognize the ARM data processinginstructions, which have the following format:
Bits 31:26 111000 Bit 25 I bit Bits 24:21 opcode Bit 20 S bit Bits 19:16 Rn Bits 15:12 Rd Bits 7:0 immediate value (when I=1) Bits 3:0 Rm (when I=0)
All other bits will be 0.
The sixteen operation codes are given in the following table:
Opcode Mnemonic Opcode Mnemonic 0000 and 1000 tst 0001 eor 1001 teq 0010 sub 1010 cmp 0011 rsb 1011 cmn 0100 add 1100 orr 0101 adc 1101 mov 0110 sbc 1110 bic 0111 rsc 1111 mvn
5. Your support module will produce ahuman-readablerepresentationof a machine language instruction which is in the same format as ARM assembly language instructions. Registers will appear as the character“r”, followed by a decimal number between 0 and15. Immediate constants will appearas the characters“#0x”, followed by a hexadecimal number. For example:
Instruction Human-readable form e086a007 add rl0, r6, r7 e096a007 adds rl0, r6, r7 e286a007 add rl0, r6, #0x7 e1520003 cmp r2, r3 e1a01003 mov r1, r3
6. Note thatthe functions inyour supportmodule cannot perform any input or output operations. All communication betweenthe driver module and the support module will be done via the two arguments to function“decode”.