Hi Team:
In the production stage, it was found that some devices crashed after the program was programmed, and the crystal oscillator did not vibrate after being powered on again; through hardware, manually adding a low level to the Pin35 RESET pin for external reset, the device still did not respond, but on this pin Adding a VCC3.3V voltage can wake up the device, and the work is normal; but once the power is turned off, it returns to the dead state, and when a high level 3.3V is added to RESET, it can be woken up again;
Through screening, we found that the OK board in the production stage can be reset normally by adding a low level to the RESET pin of the device, and there is no change by adding a high level;
The voltages of the VDDS, DCOUPL and VDDR pins we measured are all normal.
1. The proportion of good ones is about half, and this is the case for others;
2. I used SmartRF Flash Programmer 2 ver1.8.2 software + XDS100V3 programmer to burn;
3. This situation is very strange. The board in question can be woken up by adding a high level to the RESET pin. After waking up, as long as the power is kept on, there will be no problem; once the power is turned off and on again, it will appear; the board is OK. There will be no such situation, the external low level enables the reset to be normal
The good and the bad ones are from the same batch of PCBs. The componenhts have been checked and there is no problem. The ground grid and power grid of the PCB have been checked and there is no problem. It is very strange.
I want to know which reason caused this.
Best regards
Galaxy
