Fully Customized High-performance Arithmetic Logical Unit Of Study Design

In this paper, the theory and practice on a high-performance 40-bit arithmetic logic unit (ALU) to carry out a full custom design. Article first studied how to design a high-performance ALU, and begined in a variety of performance comparison in adder, and carried out first binary theory and location theory in algorithms road research at carry lookahead adder(CLA). These researches focus on theoretical research in this direction. Then in the above-mentioned theoretical support, we completed designed ALU of a 40 X-DSP processor. These researches focus on practical application. We optimize the design from the design ideas about the algorithm, the logic of structure, function simulation, circuit layout planning. The results of research papers include the following:First, in theory, through the compare of performance, area, speed, contrast, etc, we designed a high-performance 40-bit ALU (adder in the tree structure of the Kogge-stone tree).Second, in the practice of application, use the method of "within the CLA external the ripple carry adder (RCA)" to design the ALU of the 40 X-DSP processor. At the same time, in order to improve computational speed of the ALU, we further design a low-16 CLA chain, using the carry skip adder(CSA) into the design idea in this adder chain.Third, in order to improve computational speed and utilize resource, we designed a C16-bit, at a clock cycle to complete the two 16-bit addition operations or complete a 40-bit addition operations.Fourth, considering the importance of the area, we will integrate the logic operations and arithmetic operations in a logical unit in order to reduce the design area. We will use the C16-bit to complete the conversion at the arithmetic operations and the logic operations.Fifth, at the stage of the functional simulation, we have proposed the partial functional simulation and the overall functional simulation in order to the accuracy of the design process.Sixth, in the layout design stage, we briefly described the circuit layout planning and overall layout.The ALU design has been successfully applied to the design of the DSP, and it has been put into production.