1. TDC 311 Digital Logic

2. Truth Tables  AND  OR  NOT  NAND  NOR  XOR  XNOR

3. Going from a truth table to a circuit ABCM00000010010001111000101111011111ABCM00000010010001111000101111011111

4. Is this circuit reduced?  Can apply Boolean algebra  Or use a Karnaugh Map

5. Common IC chips

6. Common chip terminology  SSI: 1-10 gates  MSI: 10-100 gates  LSI: 100-100K gates  VLSI: >100K  DIP  TTL  MOS  CMOS

7. Two Types of Digital Circuits  Combinational circuits – a series of logic gates  Sequential circuits – a set of logic gates with feedback  Let’s look at some common combinational circuits

8. Multiplexor  Control lines A,B,C control which input goes to output

9. Decoder

10. Comparator

11. One-bit Half Adder

12. One-bit Full Adder

13. One-bit ALU

14. Sequential Circuits  Used in computer memories  Basic unit called a latch  Circuits with feedback  Circuits move thru states

15. SR Latch S R ~Q Q S R Q ~Q 0 0 don’t 0 1 1 0 1 0 0 1 1 1 stable (or no change or quiescent) NAND gates can also be NOR gates

16. Clocked D Latch D Clock Q ~Q

17. Section of Computer Memory

18. Memory Chip 512K by 8 Memory chip 4096K by 1 Memory chip