1. Digital Design Haldun Hadimioglu Computer and Information Science 3/30/2003 CS 2204 Laboratory

2. 3/30/2003Digital Design2 CS 2204 Title : Digital Logic and State Machine Design Credits : 4 Year : Sophomore Format : Lectures and Laboratory 3-hour lectures 3-hour laboratory sessions

3. 3/30/2003Digital Design3 CS 2204 Content : Digital circuit fundamentals Theory, analysis, design Digital clock Car alarm Traffic light controller Vending machine controller Four function calculator Precursor to courses : Computer Architecture : computer design (junior) Advanced hardware design : chip design (senior)

4. 3/30/2003Digital Design4 CS 2204 Laboratory Emphasis on design 20 students per lab 2-student teams formed first week Teams do lab projects and homework How to approach a large design Problem analysis and solving

5. 3/30/2003Digital Design5 CS 2204 Laboratory Introduces current digital design techniques and tools Team-oriented, top-down, core- based design Modern hardware development environment

6. 3/30/2003Digital Design6 CS 2204 Laboratory Hardware development environment Computer Aided Design (CAD) Software : Xilinx Foundation (industry software) Simulates hardware Testing hardware : Digilent board FPGA Chip on Digilent board FPGA : Field Programmable Gate Array Emulates hardware

7. 3/30/2003Digital Design7 CS 2204 Laboratory Why CAD Design ? Circuit design and test before physical implementation Shorter and cheaper development Design objectives reached faster Speed, cost, power consumption, size, weight, reliability,..

8. 3/30/2003Digital Design8 CS 2204 Laboratory Term Project Spring 2003 : Game playing circuit Human vs machine play against each other Derived from dominoes Chance and thinking determine winner Pieces of circuit completed in 3 to 4 week experiments (deadlines)

9. 3/30/2003Digital Design9 Historical Trend Mechanical components replaced by Analog components and Digital components Analog components replaced by Digital components

10. 3/30/2003Digital Design10 Digital Revolution Computers (laptops to supercomputers) Microprocessors (Sun Sparc to Intel Pentium 4) Car engine controllers Calculators Video games CD Players Digital cameras

11. 3/30/2003Digital Design11 Benefits of Digital Circuits Moore’s Law holds since the 1960s Every two years, number of transistors on chips doubles Every two years memory size doubles Smaller size devices

12. 3/30/2003Digital Design12 Digital Chip Electronic components are placed in Die area in center of the chip There can be  50 million components  transistors on a microprocessor die A chip The die

13. 3/30/2003Digital Design13 Is It Always A Chip ? NO ! Design on computers kept as Circuit diagrams : traditional Hardware Description Language (HDL) programs : since 1980s Companies license their design as Intellectual Property (IP) Circuit diagram/HDL program files Used as core circuits

14. 3/30/2003Digital Design14 Digital Circuits A digital circuit consists of Gates and Flip-Flops on chips All chips on Printed Circuit Boards (PCBs) 114 2 4 5 6 7 3 8 9 10 11 12 13 A 4 A 3 A 2 A 1 Y 4 Y 3 Y 2 Y 1 V cc GND B 4 B 3 B 2 B 1 7408 AND gate Chip Notch

15. 3/30/2003Digital Design15 CS 2204 Digital Components Gates Flip-flops AND OR NOT k m k + m OR gate k m k.m k k AND gate NOT gate (inverter) D Q C D Flip-flopJ-K Flip-flop Q Q Q C J K

16. 3/30/2003Digital Design16 A Digital Circuit Car seat-belt alarm Alarm sound if engine is running AND seat-belt is NOT fastened Digital circuit engine Seat belt alarm AND Seat belt engine AND OR NOT alarm

17. 3/30/2003Digital Design17 Another Digital Circuit a b AND OR NOT y(a, b, c) p q r c Digital circuit a b y(a, b, c) c if a is 0 => y =a if a is 1 => y = c Circuit Diagram (Traditional)

18. 3/30/2003Digital Design18 The Same circuit --MULTIPLEXER --VHDL STRUCTURAL MODELING entity multiplexer is port (A, B, C : in BIT; y : out BIT); end multiplexer; architecture structure of multiplexer is signal p, q, r: BIT; begin p <= NOT a; q <= p AND b; r <= a AND c; y <= p OR q; end structure; Digital circuit a b y(a, b, c) c if a is 0 => y =a if a is 1 => y = c VHDL Program !

19. 3/30/2003Digital Design19 1-bit Adder Design A 1-bit Adder, Full Adder : a b ci s co 1-bit Adder a ci b co s 0 0 0 1 1 0 1 1 0 0 0... 1 0 0 0 1 0 1 1 1

20. 3/30/2003Digital Design20 The 1-bit Adder Circuit Diagram

21. 3/30/2003Digital Design21 Designing the 1-bit Adder --FULL ADDER --STRUCTURAL MODELING entity fulladder is port (A, B, CIN : inBIT; SUM, COUT: outBIT); end fulladder; architecture structure of fulladder is signal s1, s2, s3,s4,s5: BIT; begin s1 <= A xor B; SUM <= s1 xor CIN; s2 <= A and B; s3 <= B and CIN; s4 <= A and CIN; s5 <= s2 or s3; COUT <= s4 or s5; end structure; VHDL Program