hi

Iam doing project on optimization process and in that project we need the verilog code of the kogge-stone adder for 4-bit.

In this regard please send the verilog code for 4-bit kogge-stone adder.



thanks and regards,
hari

Kogge-Stone adder Verilog code
KOGGE-STONE ADDER:

The KoggeStone has low logical depth, high number of nodes and minimum ventilation. While a high count of nodes implies a larger area, low logical depth and minimum fanout allow for faster performance
There are mainly three computational stages in KoggeStone Adder. They are:
1. Preprocessing
2. Carry the generation network
3. Post Processing

Pre-processing stage:
Preprocessing is the first stage in which the generation and propagation signals of all input pairs of signals A and B are generated separately for each bit. The logical equations of propagation and generation signals are given by the following equations:

Pi = Aix o Bi ... (1)
Gi = Aiand Bi ... (2)

Lead Generation Stage:
Lead generation is the second stage of the KSA. In this stage, the carries of all the bits are generated separately for each bit. They are divided into smaller pieces and this overall process is carried out in parallel for all bits. Carry generate and Carry propagate bits are used as intermediate signals and their logic
The equations are given as follows:

CPi: j = Pi: k + 1 and Pk: j ... (3)
CGi: j = Gi: k + 1 or (Pi: k + 1 and Gk: j) ... (4)

Post Processing Stage:
This is the final step or step of the KSA that is common to all types of adder, ie, the sum of the bits given by logical equations (5) and (6):

Ci-1 = (Pi and Cin) or Gi ... (5)
Si = Pix or Ci-1 ... (6)