AGIB027R29A1E2VR3 programming issue due to PMBus

[srgp]

Hello,

In our custom hardware we are using AGIB027R29A1E2VR3 device.

while programming .sof we are getting following error.

Error(18948): Error message received from device: External hardware access error. (Subcode 0xC80E, Info 0x00000047, Location 0x00001800)
Error(22248): The first I2C command has failed, no response from Voltage Regulator. Verify the address used in Quartus project matches that of the Voltage Regulator, inspect the PMBus/I2C bus traffic, pull-ups, bus contention, etc. The 'info' field of this error contains the target I2C address.
Error(209012): Operation failed

When we check schematic we found PWRMGT_SCL and PWRMGT_SDA pins are not connected.

As per documentation "When a –V or –E power option device is used, you must enable the SmartVID connection between the device and the VCC voltage regulator to allow the FPGA to directly control its core voltage requirements."

as we are using -V device, as per intel PWRMGT_SCL and PWRMGT_SDA connection is mandatory.

Please anyone can confirm FPGA programming failure is because of missing PMBus connection and if yes is there any way to bypass SmartVID feature(use -V device as -F which does not require SmartVID)

any workaround for SmartVID feature.

Thank You. 

[Farabi]

Hello, I am still checking with our internal team to get the solution for your issue. I will get back to you as soon as possible when I have the information.

regards,

Farabi

[Farabi]

Hello,

I am sorry to keep you waiting.

I was confirming with experts and engineering if we can bypass the smarVID PMBUS signals.

Unfortunately, the PMBUS is compulsory for Agilex devices. The reason as below:

1. The power requirement for each silicon is different.
2. for example, the voltage requirement for one silicon, VCC is 0.8V, but the actual power required for this particular silicon is 0.8234V.
3. This information on voltage required must be feedback to voltage regulator so it will provide the exact voltage to the device.
4. This voltage requirement will vary between silicon but the range is still within the spec published in the datasheet.
5. So PMBUS signal is compulsory for powering up the Agilex devices. If there is no PMBUS signals, the Agilex can't power up successfully.

regards,

Farabi

[Farabi]

Hello,

I have confirmed the answer, and I also have checked with experts about the request to bypass the PMBUS.

I am setting this case to close pending now.

regards,

Farabi