​Objectives

• ​Define and understand the functions of the logic gates

• ​Identify and use the standard symbols for logic gates

Watch video about logic gate​

... And answer questions afterwards​

​https://youtu.be/ZoqMiFKspAA

​Logic Gates

• ​Computer is an electronic device which designed to process digital signal

• Computer is made with (millions of) different logic gates

• ​Connecting logic gates allows computers to manipulate the input data and eventually produce complicated results (e.g. math operations)

​NOT gate

• ​Invert the input signal

• ​such that:

  • ​NOT (1) => 0

  • ​NOT (0) => 1

• ​or we can say:

  • ​NOT True => False

​AND Gate

• ​AND gate only gives 1 if both A AND B is 1

​OR Gate

• ​OR Gate gives 1 except both inputs are 0

​Combining Logic Gates

​Consider the following circuit

​Create truth table to work out the answer. Need to create intermediate labels to help.

​Example 2:

​Conclusion

• ​Computers composed of logic circuits

• ​Basic Logic gates: NOT, AND, OR

• ​Truth table