We have a new board with an combined eMMC + LPDDR3 RAM from Micron which we can't connect to. We can use NXPs DDR Test Tool to download our configuration and then read/write registers in the CPU without problems, but if we try to access the external RAM the processor hangs until we reboot. We can also not measure any DDR clocks or other signals (do not have access to all of them).
Doing the same on the EVM board with the exact same configuration file we can measure a DDR clk, read/write registers, and trying to access external RAM does not make the processor hang. We can off-course not use the RAM because it is the wrong configuration.
It must therefore be a hardware difference that causes this, but what?