The JESD204_PHY IP core generates the clocks and rxoutclk
at the correct frequency to use as core_clk
. However, the output phase of these clocks varies from reset to
reset. This means that for JESD204 interfaces, the JESD204_PHY IP core outclock
ports might only be used to drive core_clk
when Subclass 0 is used, and deterministic latency
is not required. For systems that require deterministic latency and therefore use
Subclass 1 or Subclass 2, the JESD204_PHY IP core outclocks
should not be used.