Open blockchain4trust opened 1 year ago
Are you saying that out of the 50 PCBs, 1 of them has a failed DDR, while the other 49 are fine? Please check for any cold soldering issues on the PCB. Based on our experience, the probability of DDR failure in NUC980 is extremely low, and the ICs are tested before leaving the factory. There should be no DDR failures under normal operating conditions.
This small batch of NUC980 PCB has a total of 50 pieces, and 5 pieces have Err-DDR, with a 10% defective rate.
The welding fault was ruled out, because this is machine SMT production, there can be no 10% error rate.
There is a clue: after the appearance of Err-DDR, if the nRST<-+-> GND NUC980 occasionally works.
What exactly causes an Err-DDR error? Please provide a process for troubleshooting intentionality, thank you.
It could be related to the board voltage or other issues. Please reflect the problem through the purchasing channel from where you acquired the IC. Here, we can only provide software BSP-related inquiries and cannot address hardware issues.
Thank you for your suggestion. The Err-DDR error on the NUC980 mentioned above is caused by hardware power supply timing.
The faulty version of the PCB uses the power chip EA3036, which has three power supply sequences of 1.2V/1.8V/3.3V for pmu. The power-on sequence of the NUC980 cannot be matched, resulting in startup failure.
Please refer to "NUC980 Hardware Development Guide_V1.0" for the power-on sequence. https://www.nuvoton.com.cn/resource-download.jsp?tp_GUID=DA00-NUC980-1¤tFolder=/products/microprocessors/arm9-mpus/nuc980-industrial-control-iot-series/
Now according to the DC-DC design power supply officially recommended by nuvoton, there is no Err-DDR error in a small batch of 30 PCBs.
For DC-DC power supply design, please refer to "HW_NK-980IoT_V1.0" https://www.nuvoton.com.cn/resource-download.jsp?tp_GUID=UG1020190308162722¤tFolder=/products/microprocessors/arm9-mpus/nuc980-industrial- control-iot-series/
As shown in the figure above, NUC980 has an Err-DDR error and fails to boot from USB / SD card / SPI Flash
The DDR file imported in NuWriter is NUC980DK61Y.ini which is consistent with the NUC980 chip model.
Incidentally, a total of 50 NUC980 PCBs have been produced, and currently there is 1 Err-DDR error