Hi，I have a custom board with IMX6Q and DDR3(2GB).
Using the tool of DDR Stress tester,432MHz pass,but 452MHz fail.
I download the special uboot and image using manufacturing tool (imx_usb), but I don't see any serial port messages. Last week, there are some messages print out, but now it doesn't work.
I check the follows:
1/ the clocks (24MHz and 32.768KHz) are fine;
2/ the power-up sequence meets the arm's requirement;
3/ the voltages for arm and DDR3 are fine. but there is some ripple on DDR3 power(between +-30mV).
4/ using the fly-by topology. terminating resistors have changed from 22ohm to 47ohm, but no effect.
Now, what should I do?