The LPC11C24 user program can be run at the beginning, but after a few months of testing, serveral chips enter the ISP abnormally, and then each time after power-on, they still enter the ISP mode. Only by erasing the chip program and reprogramming can it return to normal. I have detected that the ISP pin and power pin using a oscilloscope and when LPC11C24 is power on, the ISP pin is high level. It seems that it is not a hardware problem, so I suspect it is a software problem. Is there another way to enter ISP mode?