Abstract: Protocols are needed for efficient data communication over network. They are specified for each layer of the OSI or TCP/IP reference model by standards engineering organization. HDLC i.e. High level data link control protocol is one of the protocols defined by International Organization for Standardization (ISO) for data link layer of OSI reference model. HDLC is bit oriented protocol and it is most widely used in the network. There are different methods of designing and implementing the protocol. This paper presents different approaches of designing the HDLC protocol using hardware description language and its implementation using software tools.

Keywords: HDLC, VHDL, FCS, FPGA, Verilog HDL, Xilinx.