The following figure shows that IODELAY elements are used by the transmitter logic. An IDELAYCTRL module must therefore be instantiated in the design. For the RGMII, this is included in the <component_name>_support level, included in the core, if the Shared Logic option is selected.
Figure 1. 1 Gbps RGMII Transmitter and Clock Logic for 7 Series Using HP
I/O
