A measured window should not be perfectly open.
The non-ideal rise/fall times on an actual DRAM interface will erode margin.
Typical eye widths are greater than 80/128ths of a DDR bit time.
The attached memory test has fixed the issue.
To use it, generate a Vivado 2014.1 memory test and replace the attached test01.c file.
This issue is fixed in Vivado release 2014.2.
|Name||File Size||File Type|