The MK64FN1M0VLL12 samples I ordered from the official website of NXP, a total of 5 pieces, were tested on the minimum system I drew. Saw-tooth waves occurred on reset pin of all chips, and the chip was reset all the time. As a result, the chip could not be connected to jlink, the program could not be downloaded, and flash could not be erased.JLINK also cannot identify the chip, may I ask what is the reason?I welded the old chip that could be used normally to the minimum system, and the program could be downloaded normally, indicating that there should be no problem with the minimum system.This batch of samples are welded to other PCB, and the same phenomenon occurs. The reset pin has saw-tooth wave, and the voltage is about 1.28v. Also, i cannot unlock with unlock kinetis command in jlink commander. Unlock timeout will be prompted.