We have been starting to see questions about support for DDR4 SDRAM devices, which are gradually becoming available.
We have published a guide to using JTAG to test DDR4 memory on the XJTAG website. It contains a link to slides used at a recent presentation on the subject.
Support for DDR4 devices will be coming soon to the XJEase library, and so will be made available to users with a maintenance agreement.
If your need to test DDR4 memory is more urgent, please contact us for assistance!