PMBus is used to control the external power module.
Refer the following link especially the "Table 9. Intel MAX 10 Design Components" for PMBUS,
Let me know if this has helped resolve the issue you are facing or if you need any further assistance.
(This message was posted on behalf of Intel Corporation)
If we use voltage regulators
with enable pin input in order to control power up & down sequence
Does Cyclone 10 FPGA has
additional power requirements that require a PMBus control?
PMBus is used to control the power management controller. It is meant for controlling power up and power down sequences. Thus, the connection is between MAX Device or Microprocessor Host and Power Management Controller Devices only.
You may refer to figure at link below for more information about the connection: