用C语言代写ARM指令集解析器小程序，熟悉ARM指令。

Assignment Overview

This assignment develops familiarity with the instruction set architecture of the ARM microprocessor.

Assignment Deliverables

The deliverables for this assignment are the following files:

• proj11.makefile - the makefile which produces proj11
• proj11.support.c - the source code for your support module
• proj11.driver.c - the source code for your driver module

Be sure to use the specified file names and to submit them for grading via the CSE handin system.

Assignment Specifications

The program will simulate some of the actions taken during the fetch-execute cycle for the ARM microprocessor.

1. You will develop a support module which calculates the value which should be used to update the PC register at the end of the execute stage in the fetch-execute cycle. The interface to the support module is through function update, which is declared as follows: unsigned update(unsigned PC, unsigned IR, unsigned CPSR);
   The first argument is the current contents of the PC register, the second argument is the current contents of the IR register, and the third argument is the current contents of the CPSR register.
   Based on that machine language instruction in the IR register, function update will compute and return the next value of the PC. The value zero will be returned for illegal machine language instructions.
   The support module will consist of function update 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 will not call function scanf or function printf.
2. You will develop a driver module to test your implementation of the support module. The driver module will consist of function main and any additional helper functions which you choose to implement. All output will be appropriately labeled.
   Your driver module may not be written as an interactive program, where the user supplies input in response to prompts. Instead, your test cases will be included in the source code as literal constants.

Assignment Notes

1. Your driver module and your support module 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 proj11.makefile), and that makefile must produce an executable program named proj11.
4. Note that the functions in your support module cannot perform any input or output operations. All communication between the driver module and the support module will be done via the three arguments to function update.
5. This project will focus on a subset of the ARM machine language instructions. Bits 27:26 of the IR identify the category to which a machine language instruction.
6. The following describes the format and actions performed by Branch instructions.
   When the condition field indicates that the branch should be taken, the following computation is used. Otherwise, the default computation for all instructions is used.
7. Machine language instructions which do not meet the criteria given above are to be processed as illegal instructions.