Optional MDIO Arrangement. In systems where a single MDIO bus (MDC and MDIO) is shared between multiple CFP8 modules, the MOD_SELn pins override the internal CFP8 module address. When MOD_SELn is asserted low, the CFP8 module responds to any address. This enables the host to write unique module addresses to each CFP8 module. See 3.2 for more details.
