1. ITEC 352 Lecture 3 Low level components(2)

2. Low-level components Review Electricity Transistors Gates Really simple circuit

3. Low-level components Review What are

4. Low-level components Review #2 What does this turn into?

5. Low-level components Review 3 What does this do?

6. Low-level components 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

7. Low-level components Digital Circuits. Consider the following digital circuit. Express it as a Boolean algebra expression. –i.e., F = …? (in terms of A, B, C) –G = …?

8. Low-level components More Find the boolean expression Can you optimize it?

9. Low-level components Combination al Logic Circuits formed using gates. –Key issue: no memory is used in building these circuits.

10. Low-level components 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.

11. Low-level components Example circuit Multiplexer: Determines which input will reach output

12. Low-level components 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

13. Low-level components Summary Boolean algebra Truth tables Mux