When using Intel® Stratix® 10 and Intel Agilex® 7 FPGAs, CONF_DONE and INIT_DONE signals typically go low in less than 1 ms after nCONFIG goes low.
In PMBus (SmartVID) Agent mode, it may take a longer time for the Secure Device Manager (SDM) to de-assert the CONF_DONE and INIT_DONE, depending on when the VOUT_COMMAND is issued by the external host.
In this mode, a handshake between the PMBus host and FPGA is required to adjust the core power supplies to the nominal value after nCONFIG goes low.
The SDM de-asserts the CONF_DONE and INIT_DONE signal only after receiving the VOUT_COMMAND from the external host.
This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 21.1.