脉宽调制PWM的VHDL实现（国外英文资料）.docVIP

脉宽调制PWM的VHDL实现（国外英文资料） PWM The design of the First, the principle of experiment Pulse width modulation is a common method of motor control in industry. The basic principle is the measurement of the width of the pulse. On the implementation It is commonly used as a waiting period signal to sample the modulating signal, compare the modulation signal and the signal size of the carrier, and convert it to a digital letter of zero The size of the pulse width modulation is achieved. System description Triangular wave generator The comparator CLKData [0... 7] output figure one PWM Schematic diagram A basic PWM The generator needs a standard signal and a target signal to compare. This system describes at least one triangular wave generator and a comparator. The structure is shown in the figure. Module design 1. Triangular wave generator The triangle wave generator is essentially a counter, Under the clock signal, the counter continues to add and subtract operations In another signal logic, it is added and minus one at zero and one. This logic is reversed when the number is highest, based on this When you define the initial conditions of the circuit, you can realize the periodic triangle wave. define Reset the port RST And the clock port CLK and Output port tri_data ; Define a logical signal to add or subtract updown and Output register tri_data_temp It is. Define two in action The process Describe the process of adding and decreasing counters. When writing in a language, it is important to be aware of the selection of the initial value of the output, choosing zero or one that corresponds to the judging jump condition, otherwise It can continue to be at zero or the maximum of the triangle and cannot jump. 2. The comparator The comparator call QuatusII the MegaWizard plug-in - In the Manager The comparator in the library LPM_COMPARE set The output is more than the output VHDL Language source file It is. 3. The top engineering Capture. PNG In the top-level project, call the pre