A multimemory access method for use in FPGA designs

In order to implement nonlinear functions including sine function and cosine functions in embedded programmable logic devices (EPLD), a memory-based lookup table is often used to obtain the correct result. However, the traditional memory-based lookup table requires a large amount of embedded array blocks (EABs). In this paper, we present an improved memory-based lookup table that reduces memory resources. This reduction allows for implementation in smaller, lower cost devices or allows for more functionality to be introduced in larger devices. We term this approach the multimemory access method (MMAM). The target device for this research is the Altera FLEX EPFI0K20RC240-4. In addition, we present an efficient VHDL-based implementation of the sine function in comparing with the MMAM algorithm to the original memory-based lookup table implementation.