In this paper, we describe a slave chip based on the Profibus-DP protocol and a system board to verify the developed slave chip. The Profibus-DP protocol is designed using VHDL and implemented on FPGA. The system board adopting the developed FPGA is designed FPGA is designed in which the firmware is implemented on Intel 8051 by using C language. Among the Profibus-DP protocols, low level layers from the physical layer to the data link layer is implemented in the form of hardware that we are able to greatly reduce the CPU load in processing protocols, and then higher layers could be processed by software. These technologies result in an IP to make terminal devices in the distributed control systems. Therefore, many digital logics as well as communication logics can be implemented onto SOC(System On a Chip) and it could be applied to various fieldbus-related areas.