Arithmetic Circuit Designs

One of the most important categories of circuits that we need to design for FPGA or ASIC implementation is the arithmetic circuits. Basic arithmetic circuits are add, subtract, multiply, divide; unsigned or signed. All these circuits are computationally intensive and, therefore, conventional methods are not sufficient. We will have to base our designs on what is popularly known as pipelining in order to speed up the processing. The throughput is substantially improved by building a high degree of parallelism in our designs, of course at the cost of additional chip area. The arithmetic circuits presented in this chapter basically stems from specific applications such as DCTQ, which design will be presented in a later chapter. We will cover fixed-point arithmetic and not floating point arithmetic in our designs. This is because fixed-point arithmetic is simple and takes minimum chip area.