In the process of applying your company's MCU MSP430FR6989, there is a crash situation. At present, there is 1 case in production (16 cases in the same batch of production), and 3 cases have been found in field application.
The production of faulty MCU was analyzed and tested.
1. When the machine crashes, crystal vibration and power supply measurement are normal;
2, the PCB board of the faulty MCU and the normal MCU, MCU swap, found that the welding of the faulty MCU will also crash, and the normal MCU is still normal
3, the fault MCU is placed at low temperature, cold and heat exchange test, it is found that there is a high probability of crash when the temperature changes from -20 to 5, and the probability of crash is very small at the relatively stable temperature at normal temperature
4. Remove the faulty MCU program code for hibernation operation, and no crash has been found at present
Do you have any suggestions?