combinational logic circuit design. steps create the truth table extract the boolean expression from...
TRANSCRIPT
COMBINATIONAL LOGICCOMBINATIONAL LOGICCircuit DesignCircuit Design
Steps
• Create the truth table
• Extract the Boolean Expression from the truth table or create a K-Map
• Simplify the expression
• Draw the schematic
• Build the circuit
Design a safety alarm system for a car that alerts the driver when the seatbelts have not been fastened, or when the door is ajar while the key is in the ignition.
A=Key B=Door C=Seatbelt
A B C X0 0 00 0 10 1 00 1 11 0 01 0 11 1 01 1 1
00000111 ABC
ABCABC
Boolean Expression Is:
ABC + ABC + ABC=X
Logic Problem
K-Map
XABCCABCBA XCCABCBA )(
XABCBA
Dist.
Th. 4
XABCBA 1 Th. 6
XBCBA )( Dist.XBCA )( Th. 11
XABAC Dist.
Boolean Simplification
ABC
0 0
0 0
0 1
1 1
0 1
00
01
11
10
XACAB
Create Expression & Simplify
Create Circuit Schematic
X
NAND Only Solution
MultiSIM Demo
Warning light
B=DoorA=Key C=Seatbelt
AB+AC
0V0V0V