Combinational Ckt 2

The simplified expression for half subtractor borrow is

• X+Y

• XY

• X'Y

• XY'

IC 7483 is 4 bit binary

• serial adder

• parallel adder

• serial subtractor

• parallel subtractor

The inputs to a full - adder are A=1 ,B=1,Cin=0.The outputs are

• Sum=1,Carry =1

• Sum=1,Carry =0

• Sum=0,Carry =1

• Sum=0,Carry =0

A 4 bit parallel adder can add

• two 4-bit binary numbers

• two 2-bit binary numbers

• four bits at a time

• four bits in sequence

To expand a 4-bit parallel adder to an 8-bit parallel adder, we must

• use four 4-bit adders with no interconnections.

• use two 4-bit adders and connect the sum outputs of one to the bit inputs of the other.

• use eight 4-bit adders with no interconnections.

• use two 4-bit adders with the carry output of one connected to the carry input of the other

Tags

NGSS.HS-ETS1-2

NGSS.HS-ETS1-3

If a 74LS85 magnitude comparator has A=1011 and B= 1001 on its inputs, the outputs are

• A>B =0,A<B=1,A=B=0

• A>B =1,A<B=0,A=B=0

• A>B =1,A<B=1,A=B=0

• A>B =0,A<B=0,A=B=1