Welcome CSC 480/580 – Digital Logic & Computer Design Term: Winter 2002 Instructor: William T Krieger

CSC 480 Logic Design The course 3 Common Goals 1. Learn  practice 2. Show it  good grades 3. Have fun... Well, try to have fun “I have a dream...” Details, schmetails  Main page  Everything available online (working on it)  Logistics 45 minute lecture; break; 45 minute lecture Wednesday night lab

CSC 480 Logic Design The instructor William T Krieger  BSCS UI 1983  MSCS UIC 1995  15+ years S/W experience  Co-founder Synopsys, Inc.  New to teaching… well, pretty new So... Not a logic designer Wrote software to automate logic design I’ll follow the book pretty closely End course with HDL focus (hopefully!)

CSC 480 Logic Design Why take this course? Course is required... sort of This is “core” knowledge Overcome “hardware phobia” without much pain HW versus SW... symbiotic interaction and interesting contrast: –Faster HW is making more complex SW possible –Use of complex SW in HW design is now prevasive “...replacement of the manual logic design process makes the design of complex logic much more efficient” - Mano, page 97

CSC 480 Logic Design The last 20 years or so The evolution of SW design –Object-oriented paradigm, widespread usage of high- level languages (C++, Ada, Java) –Large systems, software engineering, testing and maintenance –Distributed computing, the net, graphical debugers/GUI builders REVOLUTION of HW design –Simulation of designs before building them –Synthesis (or compilation) of functional HW design into lower-level forms (gates, transistors) –Programs can now create logic that competes with that created by the best human being! SW design is now many times faster... HW design is now many thousands time faster!

CSC 480 Logic Design What we will learn  Logic Design oCombinational design: Boolean algebra, logic minimization, logic gates oComplex combinational structures: muxes, decoder, encoder, adder, etc. oSequential design: state machines, flipflops, registers, PLD’s oHDL descriptions  Computer Design  Basic structure  Control versus datapath  Components: register, counters, memory, programmable devices, cpu  Instruction set design, microprocessors

CSC 480 Logic Design Digital Hardware Everything built upon two primary (cool) abstractions  1’s and 0’s Boolean algebra allows formal expression, simplification, manipulation, minimization (G. Boole, 18050’s) Niftily maps onto the physical world (usually voltage)  The switch Mechanism to implement boolean functions: assignment, negation, and, or Maps onto the physical world as mechanical relay, transistor (Shockley, et al 1940’s) This search continues... biological and atomic-level transistors For us, these inventions are the equivalent of fire, and the wheel.

CSC 480 Logic Design MOS transistor as a switch Transistor revolutionizes “switch”... efficient, reliable, cheap Many flavors, but CMOS is the most popular semiconductor (chip) technology –MOS = Metal-oxide semiconductor –C = complementary, typically closed switches and negative logic Example:

CSC 480 Logic Design Hardware design levels Behavior Register transfer State machines Logic gates Boolean algebra Switches (transistors) Physical devices (Si) We will focus on Register transfer level down to boolean algebra

CSC 480 Logic Design Hardware design today  The engineer’s mistress continues to be: size, complexity, speed, cost, time to market  Must work at higher and higher design levels  Hierarchical methodology promotes design reuse (that’s “object-oriented” for us CS majors)  Software tools (CAD) are the only alternative now  Automation!  Simulators used to verify designs  Designs described at a higher level (HDL) and “compiled” into lower level components  Synthesis tools optimize designs to meet specified criteria or “constraints  Analogy: Logic design & assembly language programming

CSC 480 Logic Design Logic design example Binary multiplier –Multiply A x B to get result C Input A is 3 bits: a2 a1 a0 Input B is 4 bits: b3 b2 b1 b0 Output C is 6 bits: c5 c4 c3 c2 c1 c0 –Do an example: What is 101 x 1011? –Trick What is a one bit multiply? Need a couple of adders right? Cheat where we can –Go.