In the VFC-HD board, the access to SFP eeprom, as well 1-wire is multiplexed with application-specific user-defined code. Currently, we have a hack in place that reads SFP data, stores it in register and then fakes I2C slave that is read by WRPC.

The proposal is to have two signals: "select" and "ready". Before reading SFP (and potentially other peripherals), WRPC SW would first request access and then check whether it is granted. In most boards, "select" would be looped back to "ready". In VFC-HD (and any other where needed), the signals would be actually used.

This requires small changes in HDL and SW