Design of Efficient 16-Bit Parallel Prefix Ladner-Fischer Adder
S. BabaFariddin, E. Vargil Vijay · International Journal of Computer Applications · 2013
A parallel-prefix adder gives the best performance in VLSI design.However, performance of Ladner-Fischer adder through black cell takes huge memory.So, gray cell can be replaced instead of black cell which gives the Efficiency in Ladner-Fischer Adder.The proposed system consists of three stages of operations they are pre-processing stage, carry generation stage, post-processing stage.The pre-processing stage focuses on propagate and generate, carry generation stage focuses on carry generation and post-processing stage focuses on final result.In ripple carry adder each bit of addition operation is waited for the previous bit addition operation.In efficient Ladner -Fischer adder, addition operation does not wait for previous bit addition operation and modification is done at gate level to improve the speed and to decreases the memory used.