With industrial development, embedded technology is becoming increasingly widespread and mature. ARM embedded processors, as 32-bit high-performance, low-power RISC chips, support multiple operating systems, have high clock speeds, strong processing capabilities, and are compatible with 8/16-bit devices. They can also support massive amounts of low-cost SDRAM data storage. They have gained favor across various industries, demonstrating powerful functionality and significant commercial value, especially in the control field where they are increasingly widely used. Developing motion control systems using ARM-based embedded microprocessors offers vast potential. In some low-cost motion control systems, stepper motors are frequently used as actuators. The biggest advantage of stepper motors in such applications is that they can be controlled in an open-loop manner without feedback to control position and speed. However, precisely because there is no feedback from the load position to the control circuit, the stepper motor must correctly respond to each excitation change. If the excitation frequency is not properly selected, the motor cannot move to the new position, resulting in a permanent error between the actual load position and the position expected by the controller, i.e., loss of steps or overshoot. Therefore, preventing loss of steps and overshoot is crucial for the normal operation of an open-loop stepper motor control system. Stepper Motor Acceleration and Deceleration Control Principle Step loss and overshoot occur during stepper motor startup and shutdown, respectively. Generally, the system's maximum starting frequency is relatively low, while the required operating speed is often relatively high. If the system starts directly at the required operating speed, it cannot start normally because this speed exceeds the maximum starting frequency. This can result in missed steps or, in severe cases, complete stalling. Once the system is running, if the pulse train is immediately stopped upon reaching the endpoint, the stepper motor rotor will rotate to the next equilibrium position close to the endpoint equilibrium position due to system inertia and stop there, resulting in overshoot. Therefore, acceleration and deceleration control are required during stepper motor startup and shutdown. Acceleration and deceleration control is mostly implemented in software and consists of three stages: acceleration, constant speed, and deceleration. The control curve is shown in Figure 1. Figure 1: Stepper Motor Acceleration and Deceleration Control Curve Acceleration and Deceleration Control Method Using a microprocessor to control the acceleration and deceleration of the stepper motor essentially involves changing the time interval of the output pulses. During acceleration, the pulse frequency gradually increases, and during deceleration, the pulse frequency gradually decreases. The constant acceleration algorithm is easy to operate and has good results. As shown in Figure 2, when the change of adjacent pulses is completed within the time interval Δtm, the stepper motor rotates one step. Therefore, the area of ​​the shaded part in Figure 2 is 1. Figure 2: Pulse frequency change diagram during stepper motor acceleration and deceleration. Let the frequency of the m-th step during motor acceleration be Fm, and the frequency of the (m-1)-th step be Fm-1. The acceleration is the slope of F, let it be a, then a = (Fm - Fm-1)/Δtm; Also, ((Fm + Fm-1)Δtm)/2 = 1; From the above two equations, we can deduce: A = ((fmax - f0) * (fmax + f0))/(2 * trans); Software implementation When using the timer interrupt method to control the motor speed change, the value loaded by the timer is actually continuously changed. The control pulse is issued by the timer of the ARM chip S3C4510, so the overflow frequency of the timer should be twice the control pulse frequency. The implementation function is as follows: void pulse (REG16 f0, REG16 fmax, REG16 tran, REG16 steep) { UINT16 I, A; SysDisableInt (INT_TIMER0); SysSetInterrupt (INT_TIMER0, OnTimer2); trans = tran; A = ((fmax-f0)*(fmax+f0))/(2*trans); for（i=0;i <= trans;i++） { f[i> = sqrt_16（2＊A＊i+f0＊f0）; } f0 += f0; //2f0 TMOD=0x00; //disable timer0 and timer1 TDATA0=0x2FAF080/f0;//f0=50,000,000/TDATA0 TMOD=0x03; //enable timer0 and timer1 in Interval mode step = steep + steep; //2step trans = trans + trans; tempstep = 0; //the number of pulse output = 0; status = 0; //the state of pulse, high or low SysEnableInt (INT_TIMER0); } Where f0 is the initial pulse frequency, fmax is the maximum pulse frequency when reaching the uniform speed running state, tran is the number of transition pulse steps during acceleration or deceleration, and steep is the total number of pulse steps in this program segment. Conclusion: Using a microprocessor with an ARM core, which has a high main frequency and fast instruction execution speed, it can output a high pulse frequency. Furthermore, by employing acceleration and deceleration control methods to control the stepper motor, it can achieve smooth and high-speed operation, making it very suitable for use in economical CNC machine tools, replacing the original PC-based CNC machine tools and reducing costs. It is also important to note that the development of embedded CNC systems is generally based on embedded real-time operating systems, such as UC/OS-II. The operating system itself relies on timer interrupts as the basis for scheduling. Special care must be taken when porting the operating system and selecting the timer to control the stepper motor; the two must not conflict or affect each other, otherwise the entire system will crash.