Cold Reset on MinnowBoard_MAX (Atom E38XX)

[oleg36]

The debug board MinnowBoard_MAX running the Linux operating system (Ubuntu 18.04) runs a program that reading FLASH over the SPI bus through CPU address space (address 0xffc00000). If the PMC_RSTBTN# (manual reset) signal becomes active on the SPI bus against the background of data exchange, a cold restart of the processor occurs regardless of the state of the CF9h register. A detailed study found a difference in processor behavior when activating the PMC_RSTBTN# signal: if it becomes active against the background of data exchanges on the SPI bus, then these exchanges stop, but the processor output PMC_PLTRST# does not become active (there is no transition from "1" to "0") and after about 3-4 seconds from the moment the signal PMC_RSTBTN# is activated, all secondary power voltages are turned off for 4 seconds (a cold restart of the processor takes place). If the signal PMC_RSTBTN# becomes active in the absence of SPI exchanges, then the signal PMC_PLTRST# becomes active about 16ms from the moment the signal PMC_RSTBTN# is activated and a hot or cold restart of the processor occurs depending on the state of the register CF9h. Question: What additional processor settings must be done in the background of communication on the SPI bus, to restart processor depending only on the state of the CF9h register?

[Alberto_Sykes]

oleg36, Thank you for posting in the Intel® Communities Support.

In order for us to be able to provide the most accurate assistance on this matter, we just wanted to confirm a few details about this scenario:

What is the specific model of the Intel® Procesor you are referring to?

Are you a developer?

Are you working on a project?

If that is the case, what is the project about?

Any questions, please let me know.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[oleg36]

I use MinnowBoard MAX with Intel Atom® Processor E3826. I'm a developer of a single-board computer based on a Intel Atom® Processor E38XX processor. A problem that I described was detected during software debugging. The same problem occurs when working without an OS Linux (connection to PC via RS-232). This problem is most likely on other processors in the series Atom E38xx. I'm asking for recommendations on how to eliminate the long (cold) restart of the processor during a hot restart against the background of SPI data exchange.

[Alberto_Sykes]

oleg36, Thank you very much for clarifying that information.

In reference to this scenario and in order for us to provide the most accurate assistance on this matter, I will move your thread to the proper department which is "Embedded Intel Atom® Processors", so they can further assist you with this topic.

Regards,

Albert R.

Intel Customer Support Technician

A Contingent Worker at Intel

[CarlosAM_INTEL]

Hello, @oleg36:

Thank you for contacting Intel Embedded Community.

Your consultations of the third-party board listed on your first communication should be addressed to their manufacturer. They can be found as a reference through the channel mentioned on the following website:

https://www.silicom-usa.com/contact-us/

Best regards,

@CarlosAM_INTEL.

[oleg36]

Thanks for the answer. I think this is still a problem not with a specific board, but with a processor Atom E38xx or CMC code for this processor. We have our own board with Intel Atom® Processor E38xx, developed using the schematic of MinnowBoard MAX and the recommended ROHM Semiconductor circuit based on same processor and voltage generator chip BD9596BMWV (GOJYO_BT_Schematic). The problem described above is similar on our board, although our board uses a BD9596BMWV converter different from the one used on the MinnowBoard MAX.

[CarlosAM_INTEL]

Hello, @oleg36:

Thanks for your update.

We would like to have the sources to answer your question, but it is related to a third-party design.

Due to this fact, you should contact the developer of this design to verify that your changes are compatible with their project.

By the way, you should review letter document # 632552. You should be logged into your Resource and Design Center (RDC) privileged  account to find this letter on the following website:

https://cdrdv2.intel.com/v1/dl/getContent/632552

You should fill out the form stated on the following website when you have problems with the provided website or want to update your RDC account:

https://www.intel.com/content/www/us/en/forms/support/my-intel-sign-on-support.html

Best regards,

@CarlosAM_INTEL.