CPSC 121 Lecture Notes - Lecture 3: Xor Gate, Nor Gate, And Gate

• School: UBC
• Department: Computer Science
• Course: CPSC 121
• Professor: BELLEVILLE, PATRICE

Document Summary

Cpsc 121 lecture #3 propositional logic pt. Topics included: simplifying circuits, designing circuits, light switch problem (make a light with 3 switches that all change light"s state) The inputs to this xor gate are a and c. (8) in step 5, it was concluded that a is false. Xor gate to output true, the other input must be true. (9) therefore, c is true. (10) the bottom input to the and gate is true if the input to the or gate is true. Since the upper input is always false as per step. 11, the lower input into the or gate must therefore be true. (13) the lower input of the or gate is the output of a nand gate. Nand gates produce true if not all of its inputs are true. The simplest way to represent this is through the following logical expression and circuit: answer: (~a ^ ~b ^ c ^ ~d) (self-made via logisim)