Abstract: This paper proposes a soft IP design for a motion controller. This controller can control four-axis stepper motors or digital servo motors, enabling independent positioning and speed control for each axis. It can also select any two or three axes for linear, circular, and bit-mode interpolation. The paper describes its system architecture, basic functions, and interpolation algorithm. The final design is formed into a soft IP core and implemented and verified on a Xilinx Vertex2 series FPGA. Keywords: motion control interpolation IP ASIC FPGA Abstract: This paper designs a motion controller soft IP, which can control 4 axes of either stepper motor or pulse type servo drivers for position, speed, and interpolation. Any 2 or 3 axes can be selected to perform linear, circular, and bit pattern interpolation. We describe the structure, function, and interpolation arithmetic of the motion controller. Finally, the motion controller soft IP is implemented and verified in Xilinx Vertex2 FPGA. Key words: motion control interpolation IP ASIC FPGA 1 Introduction With the rapid development of computer, control theory, microelectronics and other technologies, motion control technology has made great progress and has become a key technology to promote the new industrial revolution. Simply put, motion control is the real-time control and management of the position, speed, etc. of mechanical moving parts, so that they move according to the expected motion trajectory and specified motion parameters [1]. Early motion control technology mainly came with the development of numerical control technology, robot technology and factory automation technology. In recent years, with the continuous progress and improvement of motion control technology, motion controllers, as an independent industrial automation control product, have been applied in more and more industrial fields. At present, open motion control technology based on PC (Personal Computer) bus with DSP (Digital Signal Processing) or dedicated motion control ASIC (Application Specific Integrated Circuit) as the core has become the mainstream. Combining the information processing capability and open characteristics of PC with the motion trajectory control capability of motion controller, it has the characteristics of strong information processing capability, high degree of openness, accurate motion trajectory control and good versatility [2]. This design uses Verilog hardware description language to design a motion controller soft IP (Intellectual Property) core with a general PC bus interface, and implements and verifies it through FPGA (Field Programmable Gate Array). For details, please click: A high-precision motion controller IP core design and implementation