In GTP designs that implement dynamic rate changes, using the DRP to dynamically re-write attributes is required. Many cases require that the PCS_COM_CFG be altered. In simulation, this value will not be read out correctly from the DRP port.
Though this attribute will need to be written and verified correctly in hardware implementation, it will not adversely affect the simulation of a rate change. In simulation, incorrect values read from PCS_COM_CFG by means of DRP can safely be ignored.