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P. 311
NPP Number System, Boolean Algebra and Logic Circuits 311
A
Carry
B
Sum
3.43 Full Adder 3.43 \w$b ES>a
Definition n[a^mfm
Full Adder is a combinational logic circuit \w$c ES>a EH$ H$m§{~ZoeZb Vm{H©$H$ n[anW h¡ Omo
which performs arithmetic addition over three VrZ {~Q>m| H$m A§H$J{UVr` `moJ H$aVm h¡Ÿ&
bits. NPP
Block Diagram ãbm°H$ S>m`J«m_
Since Full Adder adds three bits, therefore My±{H$ `h VrZ {~Q>m| H$mo Omo‹S>Vm h¡ AV… BgHo$ `o hr
it has three inputs. But it has only two outputs, VrZ BZnwQ> hm|Jo VWm Xmo AmCQ>nwQ> hm|Jo, EH$ carry hoVw
one for sum and another for carry.
VWm EH$ sum hoVw…
C
A A Carryarry
Fullull
B B F
A
Adderdder
C C Su
Summ
Truth Table for Full Adder \w$c ES>a H$s gË` Vm{cH$m
A B C Carry Sum
0 0 0 0 0
0 0 1 0 1
0 1 0 0 1
0 1 1 1 0
1 0 0 0 1
1 0 1 1 0
1 1 0 1 0
1 1 1 1 1
