1. ECE 4436ECE 5367 ISA I

2. ECE 4436ECE 5367 CPU = Seconds= Instructions x Cycles x Seconds Time Program Program Instruction Cycle CPU = Seconds= Instructions x Cycles x Seconds Time Program Program Instruction Cycle

3. ECE 4436ECE 5367 CPU time = ClockCycleTime *  CPI * I i = 1 n ii CPI =  CPI * F where F = I i = 1 n i i ii Instruction Count "instruction frequency" Invest Resources where time is Spent! CPI ave = (CPU Time * Clock Rate) / Instruction Count = Clock Cycles / Instruction Count “Average cycles per instruction” CPI

4. ECE 4436ECE 5367 MIPS Assembly Language CPU I/O Memory ControlDatapath

5. ECE 4436ECE 5367 MIPS Assembly Language CPU Datapath (extremely simplified) Registers ALU Operand 1 Operand 2 Operation Result

6. ECE 4436ECE 5367 Basic Architecture Model

7. ECE 4436ECE 5367 Software Layer

8. ECE 4436ECE 5367 MIPS Assembly Language Notation

9. ECE 4436ECE 5367 Register (32 bits)

10. ECE 4436ECE 5367 Memory Organization 32 bits register  8 bits memory how do byte addresses map onto words? Can a word be placed on any byte boundary?

11. ECE 4436ECE 5367 Addressing Objects: Endianess and Alignment Big Endian: address of most significant byte = word address (xx00 = Big End of word) –IBM 360/370, Motorola 68k, MIPS, Sparc, HP PA Little Endian: address of least significant byte = word address (xx00 = Little End of word) –Intel 80x86, DEC Vax, DEC Alpha (Windows NT) msb lsb 3 2 1 0 0 1 2 3 big endian byte 0 Alignment: require that objects fall on address that is multiple of their size. 0 1 2 3 Aligned Not Aligned little endian byte 0

12. ECE 4436ECE 5367 Executing an Assembly Instruction

13. ECE 4436ECE 5367 Register File Execution

14. ECE 4436ECE 5367 Register File Execution

15. ECE 4436ECE 5367 Register File Execution

16. ECE 4436ECE 5367 Data Access

17. ECE 4436ECE 5367 Memory Load Operation

18. ECE 4436ECE 5367 Loading data from Memory

19. ECE 4436ECE 5367 Loading data from Memory

20. ECE 4436ECE 5367 MIPS Fields op – operation to be performed rs – first source operand rt – second source operand rd – register destination operand, gets the result of the operation. shamt – shift amount – used in shift instructions. funct – selects specific operation of opcode in op field – R-type……..

21. ECE 4436ECE 5367 MIPS Assembly Language: Instruction Set 3 different instruction formats –I-type, –R-type, & –J-type (we’ll discuss first two for now)

22. ECE 4436ECE 5367 R-type instructions R-type –Three register operands –Arithmetic & logical opcodes –Format: –Rd = destination operand (output) –Rs = source operand (input) –Rt = source operand (input) 6 bits5 bits 6 bits OpcodeRsRtRdshamtfunction

23. ECE 4436ECE 5367 R-type contd.. R-type: 6 fields R-type at work –ADD$3,$1,$2 –SUB$7,$4,$5 6 bits5 bits 6 bits OpcodeRsRtRdshamtfunction Page 90

24. ECE 4436ECE 5367 More R-type examples…… jr $31 sltu $3, $8, $9 mult $5, $6

25. ECE 4436ECE 5367 I-type instructions. I-type –Two registers and an immediate –Format: –Rt = destination operand –Rs = source operand –Immediate = a constant, also a source operand Note: immediate operand must fit into 16 bits! (Why?) 6 bits5 bits 6 bits OpcodeRsRtaddress

26. ECE 4436ECE 5367 I-type instructions contd… I-type: 4 fields I-type at work –ADDI$2,$1,32 –LUI $7,OxABCD 6 bits5 bits 6 bits OpcodeRsRtaddress !Loads & stores are the data transfer instructions!

27. ECE 4436ECE 5367 More I-type examples lw $5, 60($4) sw $5, 60($4)