The Mode Register for Rx CTLE Control MR1[A13,A6,A5] is vendor specific. Since CTLE circuits can not be typically bypassed a disable option is not provided. Instead, a vendor optimized setting is given. It should be noted that the settings are not specifically linear in relationship to the vendor optimized setting, so the host may opt to instead walk through all the provided options and use the setting that works best in their environment.