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zoltan2
zoltan2
Associate
March 19, 2019
Question

USB HNP problem on STM32?

  • March 19, 2019
  • 3 replies
  • 1144 views

Hi,

I am trying to use Host Negotiation Protocol on STM32 boards.

Two boards are connected together stm32f4-discovery (A-device) and stm32f429i-disc1 (B-Device). VBUS sensing, HNPCAP is enabled at both side.

DHNPEN bit in GOTGCTL register is enabled after SetFeature(HNP Enable) received at B-Device and HSHNPEN is set after SetFeature(HNP Enable) ACK received at A-Device.

I see, that 7.5 ms after Suspending bus D+ goes low resulting SE0 state.

But 4 ms SE0 state D+ goes high, and no OTG interrupt fired on A-Device side.

On B-device side I see HNSSCHG interrupt, but HNGSCS flag in GOTGCTL register is 0 (HNP failed). I think the reason is, that A-Device doesn't apply Pull-up within 3 ms.

What can be the reason for this behaviour? What I missed to set up to get working HNP?

Thanks in advance.

Zoltan

    This topic has been closed for replies.

    3 replies

    waclawek.jan
    waclawek.jan
    Super User
    March 20, 2019

    You probably have a much deeper understanding of the OTG machine of the Synopsys USB module than anybody else here, so don't hold your breath waiting for a relevant answer.

    For the less relevant ones, have you had a look at the OTG part of the SPL-based en.stm32_f105-07_f2_f4_usb-host-device_lib.zip ?

    JW

    zoltan2
    zoltan2Author
    Associate
    March 21, 2019

    Hi Jan,

    Thanks for replying.

    I already know this code, and double checked if it matches my code.

    Unfortunately I haven't found any working example for HNP on STM32, which could be helpful for me.

    Best Regards

    Zoltan

    MChoh
    MChoh
    Associate
    May 1, 2019

    Hi Mr. Zoltan,

    I am facing the exact same problem that no OTG interrupt is fired on the A-Device. Did you manage to get OTG working? It would be great if you can help me. Thanks.

    Best Regards,

    Mughees

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