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                                样例使用说明
                             Sample Description
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功能描述：
此样例是对高级定时器功能“六步PWM的产生”的演示，通过systick中断作为COM commutation
事件的触发源，实现（无刷电机的）换向。

Function descriptions:
This sample demonstrates advanced timer function 'six-step PWM generation',
systick interrupt as COM commutation event trigger source to achieve commutation
(brushless motor).
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测试环境：
测试用板：PY32T092_STK
MDK版本： 5.28
IAR版本： 9.20
GCC版本：GNU Arm Embedded Toolchain 10.3-2021.10

Test environment:
Test board: PY32T092_STK
MDK Version: 5.28
IAR Version: 9.20
GCC Version: GNU Arm Embedded Toolchain 10.3-2021.10
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使用步骤：
1. 编译下载程序到MCU，并运行
2. 使用逻辑分析仪观察引脚PB12/PB13/PC13/PC11/PC5/PC6的波形

Example execution steps:
1. compile and download the program to MCU and run it;
2. Observe PB12/PB13/PC13/PC11/PC5/PC6 waveforms with logic analyzer
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注意事项：
PWM时序如下：
        第一步      第二步      第三步      第四步      第五步     第六步     
CH1      1           0           0           0           0          1          
CH1N     0           0           1           1           0          0          
CH2      0           0           0           1           1          0          
CH2N     1           1           0           0           0          0          
CH3      0           1           1           0           0          0          
CH3N     0           0           0           0           1          1          

CH1  (PB12)   |||||||_________________________________||||||||||||||_________________________________|||||||
CH1N (PB13)   _______________||||||||||||||||_______________________________||||||||||||||||________________
                                  
CH2  (PC13)   _______________________||||||||||||||||_______________________________||||||||||||||||________
CH2N (PC11)   |||||||||||||||________________________________|||||||||||||||________________________________
                                  
CH3  (PC05)   _______||||||||||||||||_______________________________||||||||||||||||________________________
CH3N (PC06)   ________________________________|||||||||||||||________________________________|||||||||||||||

Notes:
The PWM timing is as follows:
       Step 1      Step 2      Step 3      Step 4      Step 5     Step 6     
CH1      1           0           0           0           0          1          
CH1N     0           0           1           1           0          0          
CH2      0           0           0           1           1          0          
CH2N     1           1           0           0           0          0          
CH3      0           1           1           0           0          0          
CH3N     0           0           0           0           1          1          

CH1  (PB12)   |||||||_________________________________||||||||||||||_________________________________|||||||
CH1N (PB13)   _______________||||||||||||||||_______________________________||||||||||||||||________________
                                  
CH2  (PC13)   _______________________||||||||||||||||_______________________________||||||||||||||||________
CH2N (PC11)   |||||||||||||||________________________________|||||||||||||||________________________________
                                  
CH3  (PC05)   _______||||||||||||||||_______________________________||||||||||||||||________________________
CH3N (PC06)   ________________________________|||||||||||||||________________________________|||||||||||||||
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