Prof. John Nestor ECE Department Lafayette College Easton, Pennsylvania ECE Computer Organization Lecture 23 - Course Review December 5, 2003

ECE 313 Fall 2003Lecture 23 - Review2 Solution - Exercise 6.1  Clock cycle time for single cycle implementation:  10ns (was 8ns)  Single-cycle completes 1 instruction / cycle  10ns / instruction  Clock cycle for time pipelined implementation:  4ns (was 2ns)  Pipelined implementation completes 1 instruction / cycle  4ns / instruction  Speedup = 10ns / 4ns = 2.5

ECE 313 Fall 2003Lecture 23 - Review3 Solution - Exercise 6.2 Forward to lower input of EX

ECE 313 Fall 2003Lecture 23 - Review4 Solution - Exercise 6.4  Dependencies add $2, $5, $4 add $4, $2, $5 sw $5, 100($2) add $3, $2, $4  All dependencies can be resolved via forwarding  Reminder: load-use can’t be resolved with forwarding (stall required): lw $6, $8, $9 add $10, $6, $7

ECE 313 Fall 2003Lecture 23 - Review5 Solution - Exercise 6.8

ECE 313 Fall 2003Lecture 23 - Review6 Solution - Exercise Hit / Miss Ref Address in Cache Block 15 MISS MISS 17 MISS 19 MISS 56MISS 9 11 MISS 4 43 HIT MISS 6 HIT References Cache Contents

ECE 313 Fall 2003Lecture 23 - Review7 Solution - Exercise 7.9  Each block contains:  4 32-bit words  1 16-bit tag  1 Valid bit  Times 4096 blocks  593,920 bits  74,240 bytes

ECE 313 Fall 2003Lecture 23 - Review8 Solution - Exercise 7.15  Average Memory Access Time = Hit Time + Miss Rate X Miss Penalty  Information Given:  2ns clock period  1 cycle access time on hit  20 cycle access time on miss  Miss rate: 0.05 misses per instruction  Solution:  AMAT = 2ns X 40ns = 4ns

ECE 313 Fall 2003Lecture 23 - Review9 Roadmap for the term: major topics  Overview / Abstractions and Technology  Performance  Instruction sets  Logic & arithmetic  Processor Implementation  Single-cycle implemenatation  Multicycle implementation  Pipelined Implementation  Memory systems  Input/Output

ECE 313 Fall 2003Lecture 23 - Review10 Course Review: Important Topics  Chapter 1 - Computer Abstractions and Technology  The 5 basic components of a computer system  Technology Trends  Chapter 2: Performance  Defining performance as execution time  Basic Metrics Execution time Number of instructions / program Number of cycles / program Cycles / instruction  The performance equation and simple calculations

ECE 313 Fall 2003Lecture 23 - Review11 Course Review: Important Topics (cont'd)  Chapter 3 - Instruction Sets  Principles of Instruction Set Design  Details of MIPS Instruction Set Instruction Formats (R-Type, I-Type, J-Type) Specific Instructions  Chapter 4: Logic & Arithmetic  Number Representations  Adder Design: Basic design, carry lookahead, subtraction  Logical Operations  ALU Design  Multiplication & Division  Floating Point

ECE 313 Fall 2003Lecture 23 - Review12 Course Review: Important Topics (cont'd)  Chapter 5 - Basic Processor Design  Single-Cycle Processor Implementation  Multi-Cycle Processor Implementation Basic Implementation Microprogramming  Chapter 6: Pipelined Design  Pipelined Datatpath  Pipelined Control  Forwarding  Hazards and Stalls

ECE 313 Fall 2003Lecture 23 - Review13 Course Review: Important Topics (cont'd)  Chapter 7: Memory Systems  Memory Technology  Caches  Virtual Memory  Chapter 8: Input / Output  I/O Devices and characteristics  Disk Characteristics  Buses  Interfacing  Verilog  Combinational, sequential, and structural circuits

ECE 313 Fall 2003Lecture 23 - Review14 Possible Exam Problems...  Design Problems - add instruction or feature to...  Multicycle Processor Design  Pipelined Processor Design  Intermediate Problems  Performance  MIPS Assembly / Machine Language  Arithmetic / Logic / ALU Design ; Floating Point  Pipelining  Memory systems / caches  Verilog  Short Answer ("concept") problems - all topics