The zero-crossing point of Bemf and shifting of 30 degree later are decided by software,which considerably simplify the hardware structures that were made up of complex circuits in old days.

• 在端电压采样中，不需要采用硬件滤波，而是采用软件滤波，同时反电势过零点的测定及过零点后移相30°等的处理都由软件实现，省去了以往硬件设计时复杂的硬件电路，大大简化了系统的硬件结构。