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cgha21
Associate III
June 6, 2009
Question

a question about stm32 hid software

  • June 6, 2009
  • 3 replies
  • 685 views
Posted on June 06, 2009 at 15:01

a question about stm32 hid software

    This topic has been closed for replies.

    3 replies

    16-32micros
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 13:14

    Hi,

    ''_SetISTR((u16)CLR_CTR); /* clear CTR flag */ '' => obiously This is mistake and clearing this flag has no sense. Thank you for reporting this issue.

    Cheers,

    STOne-32.

    cgha21
    cgha21Author
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 13:14

    In the custom hid project, the hid descriptor is like following:

    0x05, 0x8c, /* USAGE_PAGE (ST Page) */

    0x09, 0x01, /* USAGE (Demo Kit) */

    0xa1, 0x01, /* COLLECTION (Application) */

    /* Led 1 */

    0x85, 0x01, /* REPORT_ID (1) */

    0x09, 0x01, /* USAGE (LED 1) */

    0x15, 0x00, /* LOGICAL_MINIMUM (0) */

    0x25, 0x01, /* LOGICAL_MAXIMUM (1) */

    0x75, 0x08, /* REPORT_SIZE (8) */

    0x95, 0x01, /* REPORT_COUNT (1) */

    0xB1, 0x82, /* FEATURE (Data,Var,Abs,Vol) */

    0x85, 0x01, /* REPORT_ID (1) */

    0x09, 0x01, /* USAGE (LED 1) */

    0x91, 0x82, /* OUTPUT (Data,Var,Abs,Vol) */

    What on earth the last 3 lines used for? A feature main item or output main item? I think the last 3 lines is useless.

    sencond question: In the endpoint descriptor,can one endpoint both used as interrupt in and interrupt out?

    third question:in function CTR_LP(),the sentence try to clear CTR flag in ISTR reg using _SetISTR((u16)CLR_CTR),but i see the CTR flag is read only in the stm32 reference manual,why?

    [ This message was edited by: cgha21 on 06-06-2009 11:08 ]

    nickkinchin
    Associate II
    May 17, 2011
    Posted on May 17, 2011 at 13:14

    Hi,

    Strange but true, I came here today to ask why in 'usb_int.c' the following line included:-

    _SetISTR((u16)CLR_CTR); /* clear CTR flag */

    when the reference manual states that it is read-only? Should this line be left out in reality? What actually clears it?

    Thanks, Nick.