The dynamic reconfiguration port (DRP) allows the dynamic change of attributes to the 100G Ethernet subsystem. The DRP interface is a processor-friendly synchronous interface with an address bus ( DRP_ADDR ) and separated data buses for reading ( DRP_DO ) and writing ( DRP_DI ) configuration data to the CMAC block. An enable signal ( DRP_EN ), a read/write signal ( DRP_WE ), and a ready/valid signal ( DRP_RDY ) are the control signals that implement read and write operations, indicate that the operation is completion, or indicate the availability of data.
For the DRP to work, a clock must be provided to the DRP_CLK port. See the Virtex UltraScale Architecture Data Sheet: DC and AC Switching Characteristics Data Sheet (DS893) [Ref 3] , for the maximum allowed clock frequency.
The CMAC block must be held in reset when you want to dynamically change the attributes through the DRP. That is, TX_RESET , RX_RESET , and the RX_SERDES_RESET[9:0] need to be asserted High.