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ITEC 352. Lecture 3 Low level components(2). Review. Electricity Transistors Gates Really simple circuit. Review. What are. Review #2. What does this turn into?. Review 3. What does this do?. Truth tables…. Draw the truth tables for the following functions:
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ITEC 352 Lecture 3 Low level components(2)
Review • Electricity • Transistors • Gates • Really simple circuit
Review • What are
Review #2 • What does this turn into?
Review 3 • What does this do?
Truth tables… • Draw the truth tables for the following functions: • F = A’B’C + A’B’C (here the ‘ stands for bar). • F = A’B + B’A
Digital Circuits. • Consider the following digital circuit. • Express it as a Boolean algebra expression. • i.e., F = …? (in terms of A, B, C) • G = …?
More Find the boolean expression Can you optimize it?
Combinational Logic • Circuits formed using gates. • Key issue: no memory is used in building these circuits.
Logic Unit • Translates a set of inputs into a set of outputs • The outputs of a CLU are strictly functions of the inputs, and the outputs are updated immediately after the inputs change. • NO MEMORY. AS SOON AS INPUT IS GIVEN (after a brief delay due to the propagational delay) THE OUTPUT SHOWS UP.
Example circuitMultiplexer: Determines which input will reach output
Uses of a MUX • Routers, Switches Etc… • To implement different other functions. • Multiplexers can be joined together easily. • E.g., Join two 4 X 1 mux’s to get one 8 X 1 mux. • Example: • Implement the majority function using a Multiplexer
Summary • Boolean algebra • Truth tables • Mux