In various embedded system applications, the high speed multi-serial communication is necessary. Various embedded systems require DSP (Digital Signal Processing) to process information & FPGA to control the peripheral devices. UART (Universal Asynchronous Receive Transmit) is designed in FPGA & connected to DSP so as to meet the real time capability of system along with compact, stable & reliable data transmission. In this paper we propose a software-implementation technique of an UART to get a platform independent UART-core for high speed serial communication in FPGA. Here the core is written in Verilog & implemented using XILINX ISE.