- Do not use separate ground for DDR and other digital logic. Can be same solid ground plane
- Do not use separate power for DDR. Can be same as VCC_1V8D.
- Move all DDR routing to layers 1 and 3, adjacent to solid ground on plane 2
We believe these design violations could erratically cause some instability. For why this instability does not occur on other Hawkboards, we are undergoing more testing. Remember that the original Hawkboard used industrial memories of DDR, so that could be a contributing factor.
We are in the process of building new boards up with the design violations fixed. After testing to make sure everything is up and running, we will post the known good design up for this community.
I thank you for being so patient. In the meantime, if you have a board that you're building, I recommend you contact us for a schematic review.