The Xillybus Forum

Hi, Eli,

Is it normal that seekable memory only be written when the interface is closed? This is what I observed during debugging.

I remember this should not be the case. So I set the ILA triggered when user_mem_wren is 1, however, the result shows that memory is written only when I close the device.

That is incorrect, right? What is the possible reason for that?

Hello,

You're correct -- a seekable interface is synchronous by its nature, and hence the data should be written on the FPGA immediately on the write() call.

It sounds like the same issue as on this thread:

viewtopic.php?f=4&t=416

Note that the problem never occurred on the driver that was available on the website, but only on some versions of the Linux kernel. So if you're using Xillybus on PCIe, you may use the driver available for download instead.

Regards,
Eli