The Secure Device Manager (SDM) in the Intel® Stratix® 10 cannot be used to read data from, or write commands to, a Voltage Regulator Module (VRM) or any other agent on the Power Management Bus (PMBus).
As a PMBus master, the Intel® Stratix® 10 PMBus interface is designed to only provide the communications across the PMBus that are required for the SmartVID logic to control the Voltage Regulator Module (VRM) that is supplying power to VCC/VCCP. Other logic in the device can not access the PMBus control logic, so the user cannot take control of the Intel® Stratix® 10 PMBus logic.
The Intel® Stratix® 10 PMBus interface also can be operated as a PMBus slave, using the PMBus Alert signal to signal the PMBus master when the SmartVID logic decides to change the VRM voltage. In this mode, the external PMBus master can use normal PMBus commands to read and control the VRM directly. This is useful when performing voltage margining of VCC during board test, or when implementing board-level power management.
