你看这个资料(http://ww1.microchip.com/downloads/en/DeviceDoc/41439A.pdf)的第二页下边标注:
In the PIC12F/LF1840 and PIC16F/LF1847, the programming high voltage is internally generated. To activate the Program/Verify mode, high voltage needs to be applied to MCLR input. Since the MCLR is used for a level source, MCLR does not draw any significant current. |
LED的负极接地