Design of Power, Area and Delay Optimized Direct Digital Synthesizer Using Modified 32-Bit Square Root Carry Select Adder

Improved speed, reduced delay, reduced size and reduced power are the most important requirements of integrated circuits. The carry select adder (CSA) is one of the most important adders in most data processors for performing arithmetic operations. The speed of parallel adders can be enhanced CSA, which widens the area to speed and eliminates propagation delays. The major problem faced in CSA is inefficient area due to the usage of multiple pairs of Ripple carry adders (RCAs) for generating the sums and carry. This research paper proposes the modified 32-bit square root carry select adder (MSCSLA) to improve the direct digital synthesizer's performance (DDS). DDS plays an effective role in the digital system due to its ability of broad frequency generation. Phase accumulator is the main component in the DDS synthesizer, where the speed of the adder is enhanced through MSCSLA. The general square root CSA still consumes more power due to the assembly of more RCAs. Hence, in the proposed approach, certain sets of RCAs are replaced with BEC1 (Binary to excess 1 convertor) to improve the speed and reduce the delay of the adder. Finally, the continuous sinusoidal waveform is attained by attenuating the high-frequency components by adopting a low pass filter. The entire structure of DDS is designed using Xilinx Verilog coding. The Simulation result shows better outcomes in terms of area, delay, power, and high performance in the DDS synthesizer compared to the existing CSAs. When compared to the existing adders, the area occupied by the proposed MSCSLA model is attained to be 636 mu m(2), the power is achieved as 50.125 mu W and delay is attained to be 1.280 ns, which are comparatively less. When comparing delay and maximum frequency with the existing techniques, the proposed model obtained minimum delay and maximum frequency. The overall power consumption by the proposed model is also attained to be lower than the existing techniques.