First Programming Assignment For MIPS R3000 Processor

1. First Programming Assignment For MIPS R3000 Processor CS 286 Computer Organization and Architecture Department of Computer Science Southern Illinois University Edwardsville Summer, 2019 Dr. Hiroshi Fujinoki E-mail: hfujino@siue.edu FirstProgram/001

2. R3000 CPU Chip Manufactured by IDT Assembly Programming using MIPS R3000 CPU What is MIPS R3000 Processor? • A 32-bit RISC CPU developed by MIPS Technologies Inc., • Used for high-performance desktops such as workstations • Many venders manufacture the chip (NEC, IDT, Toshiba) R3000/001

3. We start from here! SPIM Simulator does these for us Assembly Programming using MIPS R3000 CPU The process of assembly programming R3000/002

4. Start developing your first assembly program using SPIM Your source code file w/ “.asm” file extension Prepare your source code Three major components in your SPIM program (1) Data Section (2) Program Definition Step #1 (3) Program Body CS 286 Computer Organization and Architecture “Test.asm” FirstProgram/001

5. “#” indicates an in-line comment # ############################################################### # # Test2.asm # # # # Sample assembly code No. 2 for testing SPIM Simulator. # # This sample program is just for understanding SPIM assembler. # # # # ############################################################### # .text .globl main main: li $s1, 1 # Load "1" to register $S1 li $s2, 2 # Load "2" (decimal "2") to register $S2 add $s0, $s1, $s2 # Add register S1 and S2 and save the # result to S0 register jr $31 # Return from main (stop the program) # END OF THE LINES ############################################### “.text” label declares the beginning of your assembly program source code Declaring your program body name Overview: an assembly program source code for SPIM The program body Assembly instructions Stop your assembly program CS 286 Computer Organization and Architecture FirstProgram/002

6. The three components in your SPIM program This section is “optional” 1. “Data” Section CS 286 Computer Organization and Architecture • This is the place where you keep any constants in your program - Error message - Prompt message for user input - Any constant, such as “3.14” - Input/Output buffers (contents vary, but buffer size unchanged) • The data section is declared by “.data” assembler directive • SPIM assumes the data section at the beginning - Because the program codes are supposed to be at the end FirstProgram/003

7. The three components in your SPIM program (continued) 2. “Program Definition” Section We will see this in examples later CS 286 Computer Organization and Architecture • This is the place where you declare your assembly program • The program definition section is declared by “.text” assembler directive • The beginning label of your assembly program declared by “.globl name_of_your_beginning_label”  The program definition section should be the simplest (and shortest) FirstProgram/004

8. The three components in your SPIM program (continued) 3. “Program Body” Section We never know before. CS 286 Computer Organization and Architecture • This is the place where you write your program (assembly instructions) • You must start with the beginning label you declared - If you declare “.globl main” in program definition - You must start your program with “main:” label • Your program should be stopped by “jr $31” instruction  If you forget that, the CPU continues to execute What instructions will be executed? FirstProgram/005

9. Dissection: Program Body Section Instruction field Label field Comment field Beginning of a program Your program Stop your program CS 286 Computer Organization and Architecture main: jr $31 # Stop program FirstProgram/006

10. Open your program source code Start using SPIM This is when we start PC-SPIM for the first time CS 286 Computer Organization and Architecture FirstProgram/007

11. Specify your source code file Start using SPIM (continued) CS 286 Computer Organization and Architecture FirstProgram/008

12. Start using SPIM (continued) Once assembly program is opened, the four windows will be automatically re-loaded CS 286 Computer Organization and Architecture FirstProgram/009

13. Close-Look (1): “Register” Window “Register” window Contents of registers CS 286 Computer Organization and Architecture FirstProgram/010

14. Close-Look (2): “Text Segment” Window Assembler instructions (from your source code) Generated machine codes (in Hexadecimal expression) Address for your instructions CS 286 Computer Organization and Architecture FirstProgram/011

15. Close-Look (3): “Data Segment” Window Address of major program components are shown CS 286 Computer Organization and Architecture FirstProgram/012

16. Close-Look (4): “Message” Window Messages from SPIM Assembler are shown here CS 286 Computer Organization and Architecture Most probably, the least important window ... FirstProgram/013

17. To run your program, press this button CS 286 Computer Organization and Architecture FirstProgram/014

18. Text Segment Window Specify starting address of your assembly program (optional) CS 286 Computer Organization and Architecture FirstProgram/015

19. Examining registers for the result of program execution CS 286 Computer Organization and Architecture FirstProgram/016

20. The three components in your SPIM program (continued) CS 286 Computer Organization and Architecture FirstProgram/017

21. The three components in your SPIM program (continued) The results of program execution CS 286 Computer Organization and Architecture FirstProgram/018