Hi all,this's weird.I soldered a board to run PIC16F877A with a crystal of 12MHz.An RC reset circuit and a connector to ICD2 is implimented.That's all.I don't understand why such a simple system can be so easily interfered when I touch the chip's top with my index finger.There must have been something I have neglected.Could anyone offer me a clue?Thank you!
Hi Jay,I guess it's the latter case.
Yep,Mike,you're right.
As I went offline and retried to provoke the problem,I noticed it happened especially when my finger was close to the PGM pin.I searched through the datasheet and found all the answers on page 160.That's exactly what you guys are talking about here.The LVP was enabled in my circuit and RB3 was set as output,that's why the system went crazy with my touch.Thank you for your help.