基于FPGA的计算器，可以实现加减乘除运算功能，由于时间问题，浮点运算未能实现，其中的二进制与BCD码相互转换的模块可以使用-FPGA-based calculator, arithmetic calculation function can be achieved, due to time issues, floating-point operations failed to achieve, including binary and BCD code conversion modules t