Succeeds: propositions
Summary
Logic gates
Operation | Gate | Output |
---|---|---|
NOT | ![]() | |
AND | ![]() | |
OR | ![]() | |
NAND | ![]() | |
NOR | ![]() | |
XOR | ![]() | |
XNOR | ![]() |
hollow circle represents a negation, solid circle represents a wire intersection
Universal gates
Operation | NAND | NOR | ||
---|---|---|---|---|
NOT | ![]() | ![]() | ||
AND | ![]() | ![]() | ||
OR | ![]() | ![]() |
Half adder
- arithmetic addition of 2 single bits
- 2-bit output
0 | 0 | 0 | 0 |
0 | 1 | 0 | 1 |
1 | 0 | 0 | 1 |
1 | 1 | 1 | 0 |
Concept
Logic circuits
- circuit made up of logic gates
- fan in -> number of inputs to a gate
- every input must be connected for the circuit to work
Universal gates
- any boolean function can be built using only NOT, AND and OR
{NOT, AND, OR}
is a complete set of logic
NAND circuits
- NAND can implement NOT, AND and OR
{NAND}
is a complete set of logic- for SOP expressions
NOR circuits
- NOR can implement NOT, AND and OR
{NOR}
is a complete set of logic- for POS expressions
Application
SOP to NAND circuit
POS to NOR circuit