Hi,
here is some interesting note from a community member at the boards:
Normally the DLL (Delay-Locked Loop) should only be disabled to run RAM at very low clock speeds (for power saving). Disabling the dynamic DDR RAM clock speed might also fix the issue.
Are we running at a dynamic DDR RAM clock speed? Or is that static?
That would explain why the RAM crashes when the device is idle and the RAM controller drops the memory clock. It might be possible to turn DLL off before power save and re-enabling it when going back to full clock rate but it could be risky if that causes bus glitches during retraining/resync. DDR RAM is always a pain to get stable.
Well, DLL should be automatically disabled on self-refresh anyways (based on the Jedec doc), but maybe the RAM freezes when DLL is being enabled again...
It still means to me: If we disable DLL, then self-refresh should still work - and unless we don't run into any issues when using the RAM normally with DLL switched off, we shouldn't have any downsides, or should we?
As DLL becomes more important the faster the RAM clock is: 532MHz isn't that fast (DDR3 supports way higher clock rates) which is the reason DLL off works fine...?