Most engineering designs can be viewed as systems, that is, as collections of different components whose combined operation provides useful services. The components can be heterogeneous in nature and their interaction can be regulated (5) by simple or complex means. The interface between Hardware and Software plays a very important role in the co-design of the embedded system. Hardware/software co-design (7) means achieving system-level goals by exploiting the synergism of hardware and software through their simultaneous design. This paper shows how hardware and software interfaces (3) can be implemented using primitive interface design. Keywords: co-planning; Primitive interface; Processor; LatchIntroductionThe hardware/software interface design supports the simultaneous use of hardware and software to implement the desired function. It is widely used in embedded system design. With hardware and software interface design, a system specification is divided into hardware and software parts according to the system architecture.(12)The embedded system usually requires high performance at low cost. To meet these requirements in the application, powerful chips, such as microprocessors (MPs), microcontrollers (MCs), and digital signal processors (DSPs), and high-level programming languages ​​are used for software design.(8)Program Design primitive interfaceThe primitive interface design implements input and output, where the input interface supports the read function and the output interface supports the write functionInput interface for processorThe input interface for processor consists of the interface hardware and software interface. The behavior of the hardware interface can be described by a Verilog p......half article......idelberg, 1996.[5] Bob Moore. 'SOC should mean 'Software on Chip' '. CoWare Inc., Electronic News, October 23, 2000.[6] M. Chiodo et al. "Hardware-software co-design of embedded systems". IEEE micro, Vol.14, No.4, July-August. 1994.[7] J. Van den Hurk and J. Jess. “System-level hardware-software co-design.” Kluwer Academic, 1998.[8] Intel Inc. "MCS 51 Microcontroller Family User Manual." February 1994.http://www.intel.com/design/mcs51/manuals[9] Xilinx, Inc., 'Development System Reference Guide'. 2000.[10] Xilinx, Inc., “Xilinx Synthesis Technology (XST)-3.1i User Guide.” 2000.[11] Synopsys, Inc., “FPGA Compiler II/FPGA Express Verilog HDL Reference Manual.” May 1999.[12] Xilinx, Inc., “Xilinx Netlist Format (XNF) Specifications.” June 1, 1995.[13] Craig Peacock, "Standard Parallel Port Interface." February 1998. http://www.senet.com.au/cpeacock