项目中有用到内部比较器COMP3A,当外部电压高于内部DAC设定值的时候使PWM输出信号置位,当比较器输出为高的时候触发DCAEVT使PWM信号置位。现在发现实际值远远没到理论值时就被触发了,VDDA = 3.3V,如设定为2.5V,有时1V多就触发了,不知道是什么原因?
Comp3Regs.COMPCTL.bit.COMPSOURCE = 0; // Inverting input of comparator connected to internal DAC
Comp3Regs.COMPCTL.bit.CMPINV = 0; // Output of comparator is passed
Comp3Regs.COMPCTL.bit.SYNCSEL = 1;
Comp3Regs.COMPCTL.bit.QUALSEL = 11; // Qualification Period for synchronized output of the comparator
Comp3Regs.COMPCTL.bit.COMPDACEN = 1; // Power up the comparator and DAC logic
Comp3Regs.DACCTL.bit.DACSOURCE = 0; // DAC controlled by DACVAL
Comp3Regs.DACVAL.all = 775;
还有一个问题是,当这个ADC口当COMP使用的时候,它的ADC采样还能正常使用吗?相互间会不会有影响?