09-07-2012, 01:27 PM
NAND and NOR Implementation
[attachment=27265]
Background Information :
NAND and NOR gates is said to be universal gates because any digital system can be implemented using only one of these gates.
Digital circuits are frequently constructed with only NAND or NOR gates; because these gates are easier to fabricate with electronic components. Because of the importance of NAND and NOR in the design of digital circuits, rules and procedures have been developed for the conversion from Boolean functions in terms of AND, OR and NOT into equivalent NAND or NOR logic diagrams. NAND and NOR are called universal gates because any digital system or Boolean function can be implemented with only these gates.
NAND Implementation of Boolean functions:
Assume that all variables and their complements are available as inputs.
Find the minimum SOP expression of the function.
Draw the corresponding two-level AND-OR circuit diagram.
Replace all gates with NAND gates; learning the gates interconnections are kept unchanged.
NOR Implementation of Boolean functions:
Assume that all variables and their complements are available as inputs.
Find the minimum POS expression of the function.
Draw the corresponding two-level OR-AND circuit diagram.
Replace all gates with NOR gates, learning the gates interconnections are kept unchanged.
[attachment=27265]
Background Information :
NAND and NOR gates is said to be universal gates because any digital system can be implemented using only one of these gates.
Digital circuits are frequently constructed with only NAND or NOR gates; because these gates are easier to fabricate with electronic components. Because of the importance of NAND and NOR in the design of digital circuits, rules and procedures have been developed for the conversion from Boolean functions in terms of AND, OR and NOT into equivalent NAND or NOR logic diagrams. NAND and NOR are called universal gates because any digital system or Boolean function can be implemented with only these gates.
NAND Implementation of Boolean functions:
Assume that all variables and their complements are available as inputs.
Find the minimum SOP expression of the function.
Draw the corresponding two-level AND-OR circuit diagram.
Replace all gates with NAND gates; learning the gates interconnections are kept unchanged.
NOR Implementation of Boolean functions:
Assume that all variables and their complements are available as inputs.
Find the minimum POS expression of the function.
Draw the corresponding two-level OR-AND circuit diagram.
Replace all gates with NOR gates, learning the gates interconnections are kept unchanged.