DQS and DLL

Hello,

I am trying to understand how the DLL works to delay the DQS input.

From what I understand, the input clock to the DLL must have the same frequency as the DQS signal and hopefully not much of a phase shift.

Then, using the setting on the DLL, the DQS input signal can be delayed to arrive at a desired time (say DQ center for example).

Is this correct?

If no DLL is available, how might this delay be achieved (using IOE delay chain?)

Thank you!