Lynbrook Computer Science

February 23, 2009

AnnouncementsACSL – March 9

Digital Electronics – 2Graph Theory – 2Boolean Algebra – 1

USACO – March 13-16

Digital ElectronicsLogic “Gates”Just Boolean

Algebra!AND NAND (NOT

AND)

OR NOR (NOT OR)

XOR (Inequality)

XNOR (NOT XOR)(Tests equality)

NOT

Try it outFind all ordered triples that make this circuit

true.

SolutionConvert to boolean algebra: (A XOR B) XOR

(B OR C)Truth table: Evaluate each part individually

More challengingFind all gates

(AND/OR/NAND/NOR/XOR/XNOR) that can replace the “X” such that only one tuple makes the circuit true.

Solution