RocketIO™ X Transceiver User Guide www.xilinx.com 123UG035 (v1.5) November 22, 2004 1-800-255-7778RChapter 5Simulation and ImplementationPMA InitializationWhen the PMAINIT signal is asserted High, the PCS resets the PMA and the PCS, andloads coefficients from the PMA_SPEED attribute into the PMA. The PCS is held in resetduring this time. Figure 5-1 shows the steps that take place once the PMAINIT signal hasbeen asserted and deasserted.If the PMAINIT signal is asserted and deasserted, the PMARXLOCK signal goes Low andstays Low until configuration is complete and the receive PLL has regained lock. Note thatthe PMARXLOCK signal can assert High and Low while the receive PLL is locking.The addresses 0-14 in the PMA are loaded sequentially first, with address 15 loaded last.Address 15 is loaded four times, in the order of the power-up sequence defined by thePMA. The attribute PMA_PWR_MASK defines which sections of the PMA are poweredup. By default, the entire PMA powers “Model Considerations” up, including the linedriver.After the initialization sequence is completed, the initialization function relinquishescontrol of the PMA bus to the fabric. At this time, the user can load custom values into thePMA configuration registers.If the user would not like to depend on PMARXLOCK to indicate when the function iscompleted, a timer can be used. The period of the clock used is the reference clock dividedby two. This clock is connected internally. Refer to for start-up times.
