Dear all,
I have some booting problems on my custom board based on iMX8M mini processor.
We use PMIC PCA9450.
Processor code MIMX8MM5DVTLZAA
DDR4 DRAM code (2GB total): 2 x MT40A512M16LY-075:E
DRAM Schematics connections is the same than EVK SCH-35104_B1 (8MMINID4-CPU).
We set main voltage as follows:
- VDD_DRAM&PU = 0,9V
- VDD_DRAM_1V2 = 1,2V
We produced 14 prototipes of this board. 10 boards always boot properly and they have no problems.
The other 4 boards do not boot properly every time. Console output is following:
U-Boot SPL 2018.03-g5f7f913-dirty (Jul 03 2020 - 13:57:13 +0200)
DRAM PHY training for 2400MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 400MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training PASS
DRAM PHY training for 100MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training FAILED
DRAM PHY training for 2400MTS
check ddr4_pmu_train_imem code
check ddr4_pmu_train_imem code pass
check ddr4_pmu_train_dmem code
check ddr4_pmu_train_dmem code pass
Training FAILED
There are 2 FAILED on DRAM test so the boot process stops.
If I run RAM Stress Test "mscale_ddr_tool_v310_setup.exe" (both calibration and Stress Test) all works fine so it seems that DDR4 connections have no problems but when I use the UBOOT the booting stops after RAM tests in SPL (only on this 4 boards).
Could you help me?
Thanks
Giacomo
