Abstract : This paper proposes an embedded motion controller based on the ARM microprocessor S3C2410 and the DSP professional motion control chip MCX314As. It can be widely used in industrial control fields such as CNC machine tools and robots. This embedded motion controller features low power consumption, high performance, and low price, representing the future trend of economical industrial motion controllers. Keywords : Microprocessor; Motion control chip; Industrial control 0. Introduction Motion control systems are widely used in industrial control, but the application of embedded technology in industrial control is still relatively immature. In recent years, industrial control has placed increasingly higher demands on motion control systems. To meet the performance requirements of the next generation of motion control systems, embedded motion controllers have emerged. This next-generation motion control system, based on the combination of ARM and DSP motion control chips, fully leverages the respective characteristics of the ARM microcontroller and the professional motion control chip MCX314As, and can easily construct a high-performance embedded motion control system. 1. The MCX314As motion control chip is a DSP motion control chip developed by NOVA Electronics Co., Ltd. of Japan. It is a single-chip motion control chip capable of controlling four axes with pulse sequence outputs to drive servo motors and stepper motors. It can be used in industrial automation equipment, industrial robots, measuring equipment, office equipment, and home appliances. It can perform independent positioning and speed control for each axis, and can also arbitrarily select two or three axes from the four axes for circular, linear, and positional interpolation. The output pulse frequency is up to 4MHz, with an error of less than ±0.5 minimum interpolation unit and a magnification of 1-500. Each axis has a servo feedback input, four input points, and eight output points. It can be independently set to constant speed, linear, asymmetric S-curve addition/subtraction control, and asymmetric trapezoidal addition/subtraction control. It also has two 32-bit logic counters, an actual position counter, and a status comparison register to achieve closed-loop position control. The MCX314As motion control chip interfaces with an 8/16-bit data bus and uses command, data, and status registers to achieve 4-axis 3-linkage motion control and real-time monitoring of position, speed, and acceleration. Using this professional-grade motion control chip significantly reduces the workload of developing algorithm software and accelerates research progress. In practical applications, all extremely complex real-time motion control tasks can be handled by the MCX314As chip, while the host CPU only needs to issue a series of control instructions to the MCX314As chip to achieve various complex movements. 2. ARM Microprocessor S3C2410 The S3C2410 is a 32-bit RISC embedded processor designed by Samsung. This processor provides a cost-effective, low-power, high-performance solution for handheld devices and general applications. Based on the ARM920T core, it employs a five-stage pipeline and Harvard architecture, with a clock frequency of up to 200MHz. The ARM920T features a full-featured Memory Management Unit (MMU), independent 16KB instruction and data cache, and a high-speed AMBA bus interface. To reduce application system design costs, the S3C2410 integrates numerous commonly used resources, such as an LCD controller, NAND Flash controller, SDRAM controller, system chip select logic, and some common communication interfaces, making it widely applicable in industrial control. 3. Basic Structure of the Motion Controller 3.1 Hardware System The S3C2410 development board has a reserved system bus interface, providing signal lines based on general-purpose I/O ports, including 16-bit data lines, 12-bit address lines, chip select signals, and some read/write control signals, facilitating user expansion of application circuits. The connection between the motion control chip MCX314As and the S3C2410 processor is achieved through this standard system bus interface circuit, connecting their data lines, address lines, read/write control lines, chip select signals, and interrupt signals. The signal connection diagram between the S3C2410 and MCX314As is shown in Figure 1. As can be seen from the figure, there are chips labeled "SN74ALVC164245" between the interconnected signal lines. This is because the operating voltage of the S3C2410's I/O pins is 3.3V (theoretically it can withstand 5V), while the MCX314As operates at 5V. For safety and to increase the reliability of signal transmission, we added these "SN74ALVC164245" chips to perform level conversion and drive the signals. It should also be noted that we are using 16-bit data transmission, so the H16L8 pin of the MCX314As chip must be connected to a high level. 3.2 Software System The processing of this embedded motion control system is actually the process of transmitting data from the ARM host computer to the MCX314As slave computer. The control flowchart is shown in Figure 2. (1) When the machining program starts, the MCX314As chip is initialized. The initial speed, acceleration, deceleration, acceleration change rate, forward and reverse rotation mode, logic position counter clearing, and actual position counter clearing of the MCX314As chip are set. (2) Select the axis to be machined. The MCX314As chip has four axes: X, Y, Z, and U, all of which have the same functional capabilities and can realize four-axis three-linkage. (3) Set the selected axis mode and running parameters, including linear constant speed mode, single-step interpolation output mode, and interrupt request. (4) Initialize the position counter, that is, write the row number in the database into this counter for subtraction calculation. After processing each row of data, decrement by one. (5) Perform command and data transmission. After sending data, check the status register. After machining a section, send a signal and then send the next set of data until the machining is completed. If an interruption occurs during the machining process, first read the data of each register and save it. Wait for the machining to resume before reading and writing it out. After the entire database file is output, the data information and system status information after the system operation are saved for the next part processing, thus ending the processing. 4. Application in XY Two-Axis CNC Servo Worktable The XY two-axis worktable is a cross-shaped worktable (X and Y axes are perpendicular) driven by ball screws and rolling guides. There is one limit switch at each end of the X and Y axes. A Panasonic AC servo motor (model MSMA022A1C, power 200W, rated speed 3000r/min, rated torque 0.64Nm) is used to drive the worktable movement, and the motor driver is a Panasonic servo driver MSDA023A1A. A photoelectric encoder is used as the position feedback device (11-line 2500P/r incremental encoder coaxially mounted on the servo motor). Figure 3 is the X-axis drive principle diagram of this platform. The Y-axis drive circuit is the same as the X-axis drive circuit. In the figure, M is the servo motor and EC is the encoder. Set the servo driver's "control mode" to "position control" and the command pulse to "CW/CCW" mode. Operate the S3C2410 according to the flowchart using the MCX314As, set the corresponding motion parameters, and write function commands to complete the motion trajectory control of the platform. 5. Conclusion Motion control systems are widely used in industrial control. The MCX314As is a highly integrated motion control chip capable of four-axis three-linkage position, velocity, and acceleration control, as well as continuous interpolation and closed-loop position control in linear, circular, and bit modes. The ARM processor, with its powerful 32-bit RISC performance, small size, and low power consumption, is a high-performance processor. Using ARM and specialized motion control chips can significantly reduce R&D tasks, accelerate development speed, and allow for the creation of high-performance embedded motion control systems in a shorter time. References [1] Ye Peiqing, Wang Jinsong, Design of MCX314 motion control chip and CNC system, Beijing University of Aeronautics and Astronautics Press, 2002 [2] Yu Zhangguo, Embedded motion controller based on ARM and MCX314A, Microcomputer Information, 2005, Vol. 21, 9-2, 76-78 [3] Guangzhou Friendly Arm Technology Co., Ltd. SBC2410X User Manual Version 0.9.