Binary To Excess-1 Converter Research Articles

IJARCCE - Computer and Communication Engineering

The CSLA is used in many computational systems to alleviate the problem of carry propagation delay by independently generating multiple carries and then select a carry to generate the sum . However, the CSLA is not area efficient because it uses multiple pairs of Ripple Carry Adders (RCA) to generate partial sum and carry by considering carry input , then the final sum and carry are selected by the multiplexers (mux). The basic idea of this work is to use Binary to Excess-1 Converter (BEC) instead of RCA in the regular CSLA to achieve high speed and low power consumption. .

IJARCCE - Computer and Communication Engineering

DESIGN of power-efficient and high-speed data path logic systems are one of the most substantial areas of research in VLSI system design. In digital adders, the speed of addition is limited by the time required to propagate a carry through the adder. The sum for each bit position in an elementary adder is generated sequentially only after the previous bit position has been summed and a carry propagated into the next position. The Carry select adder (CSLA) is used in many computational systems to alleviate the problem of carry propagation delay by independently generating multiple carries and then select a carry to generate the sum . However, the CSLA is not area efficient because it uses multiple pairs of Ripple Carry Adders (RCA) to generate partial sum and carry by considering carry input , then the final sum and carry are selected by the multiplexers (mux). The basic idea of this work is to use Binary to Excess-1 Converter (BEC) instead of RCA in the regular CSLA to achieve high speed and low power consumption..

Area–Delay–Power Efficient Carry-Select Adder

In this brief, the logic operations involved in conventional carry select adder (CSLA) and binary to excess-1 converter (BEC)-based CSLA are analyzed to study the data dependence and to identify redundant logic operations. We have eliminated all the redundant logic operations present in the conventional CSLA and proposed a new logic formulation for CSLA. In the proposed scheme, the carry select (CS) operation is scheduled before the calculation of-final-sum, which is different from the conventional approach. Bit patterns of two anticipating carry words (corresponding to c <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</sub> = 0 and 1) and fixed c <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</sub> bits are used for logic optimization of CS and generation units. An efficient CSLA design is obtained using optimized logic units. The proposed CSLA design involves significantly less area and delay than the recently proposed BEC-based CSLA. Due to the small carry-output delay, the proposed CSLA design is a good candidate for square-root (SQRT) CSLA. A theoretical estimate shows that the proposed SQRT-CSLA involves nearly 35% less area-delay-product (ADP) than the BEC-based SQRT-CSLA, which is best among the existing SQRT-CSLA designs, on average, for different bit-widths. The application-specified integrated circuit (ASIC) synthesis result shows that the BEC-based SQRT-CSLA design involves 48% more ADP and consumes 50% more energy than the proposed SQRT-CSLA, on average, for different bit-widths.

Design of Low Power, Area-Efficient Carry Select Adder

Design of low power and area-efficient logic systems forms an integral part and largest areas of research in the field of VLSI Design. Addition is the most fundamental arithmetic operation. In this paper, a low power, area-efficient carry select adder is proposed. CSA is one of the fastest adders used in dataprocessing systems to perform fast arithmetic operation. Secondly, structure of carry select adder is such that there is scope of reducing the area and power consumption. Thirdly, there is scope to reduce the area by using some add-one scheme. So, a Modified Carry Select Adder(MCSA) is designed by using single Ripple Carry Adder(RCA) and Binary to Excess-1 Converter (BEC) instead of dual RCAs in order to reduce the area and power consumption with small speed penalty. CSA and MCSA structures are designed for 8-bit, 16-bit, 32bit and 64-bit. Result analysis shows that MCSA is better than CSA.

Design of 32-bit Carry Select Adder with Reduced Area

Addition is the heart of arithmetic unit and the arithmetic unit is often the work horse of a computational circuit. So adders play a key role in designing an arithmetic unit and also many digital integrated circuits. Carry Select Adder (CSLA) is one of the fastest adders used in many data processors and in digital circuits to perform arithmetic operations. But CSLA is area-consuming because it consists of dual ripple carry adder (RCA) in the structure. To reduce the area of CSLA, a CSLA with Binary to Excess-1 Converter is already designed which reduces the area of adder. But there are other techniques to design a CSLA to reduce its area. One of such technique is using an add one circuit technique. This paper proposes the design of square root CSLA (SQRT CSLA) using add one circuit with significant reduction in area. The proposed design is synthesized using Leonardo Spectrum to get area (number of gates) and delay (ns). The performance in terms of area and delay are evaluated for square root CSLA using add one circuit and are compared with existing SQRT CSLA and SQRT CSLA using Binary to Excess-1 Converter (BEC). The results analysis shows that the proposed SQRT CSLA using add one circuit is better than the existing SQRT CSLA and SQRT CSLA using BEC.

An Area and Delay Efficient Csla Architecture

Carry select adder (CSLA) is known to be the fastest adder among the conventional adder structures. Due to the rapidly growing mobile industry not only the faster arithmetic unit but also less area and low power arithmetic units are needed. The modified CSLA architecture has developed using Binary to Excess-1 converter (BEC). This paper proposes an efficient method which replaces the BEC using D latch. Experimental results are compared and the result analysis shows that the proposed architecture achieves the three folded advantages in terms of area, delay and power. Index Terms- area efficient, CSLA, low power and BEC