4 Bit Adder Using Full Adder And Half Adder. Connect first half adder to inputs a and b. Alternately 2 xor gates 2 and gates and 1 or gate.
Input of half and full adder. The full adder is usually a component in a cascade of adders which add 8 16 32 etc. We know the equations for s and cout from earlier calculations as.
As the project description is to design a 4 bit adder group members assumed they have 8 inputs which are the 2 sets of 4 bits to be added so in the design it is more efficient in terms of delay area and power to design a half bit adder for the first bit adder as there is no carry in bit for the first adder.
Even the sum and carry outputs for half adder can also be obtained with the method of karnaugh map k map. Before going into this subject it is very important to know about boolean logic and logic gates. Here is the expression now it is required to put the expression of su. The half adder has two input values a and b which represent the data bits.
