a question about stm32 hid software

cgha21 · ‎2009-06-06

Posted on June 06, 2009 at 15:01

nickkinchin · ‎2011-05-17

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.

cgha21 · ‎2011-05-17

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 ]

16-32micros · ‎2011-05-17

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.