The external GT channel DRP ports are pulled out to the core top.
• ext_ch_gt_drpdo[15:0]
• ext_ch_gt_drpdi[15:0]
• ext_ch_gt_drpen[0:0]
• ext_ch_gt_drwe[0:0]
• ext_ch_gt_drprdy[:0]
• ext_ch_gt_drpaddr[8:0]
gt_ch_drp_rdy indicates that the external GT channel DRP is ready to use, and that it is not in use by internal logic.