When we apply P2020 with DDR3 in a low-temperature environment(-20℃),
there is no output from the serial port, which is suspected to be related to DDR3 initialization.
And it is normal at room temperature, and the serial port outputs system startup status information normally.
We want to try to revise the DDR3 controller parameters (especially tRC parameters) of P2020 and the MR register of DDR3 particles, but we did not find any relevant instructions in the application manual. We hope to receive any help.
You could use QCVS DDRv tool to connect to the custom board to do validation and optimization to get optimized DDR initialization parameters and used them in u-boot software.
Please refer to DDRv user manual https://www.nxp.com/docs/en/user-guide/QCVS_DDR_User_Guide.pdf