PORTS Forum

Ports and Interfaces => USB => Topic started by: Nik on August 07, 2013, 02:36:38 am

Title: HID Report Count
Post by: Nik on August 07, 2013, 02:36:38 am

Hello,

In the HID specifications or anywhere on the internet,
I could not find the maximum number of Report Counts supported by HID.

Any help is highly appreciated.

Thanks.
Nik

Title: Re: HID Report Count
Post by: Jan Axelson on August 07, 2013, 09:51:44 am

If you mean the maximum value of the Report Count item, the low 2 bits of the Report Count tag are the number of bytes in the Report Count item. So that limits the maximum Report Count item's value to 3 bytes (FFFFFFh or 16,777,215). I don't know if any OSes choke on smaller values.

Title: Re: HID Report Count
Post by: Tsuneo on August 08, 2013, 10:00:35 am

Er.. Jan,
bSize = 3 (11b) of short item means 4 bytes
6.2.2.2 Short Items, HID1_11.pdf

Tsuneo

Title: Re: HID Report Count
Post by: Jan Axelson on August 08, 2013, 11:13:36 am

Thanks, Tsuneo!

Title: Re: HID Report Count
Post by: Nik on August 24, 2013, 05:36:47 am

Thanks Jan, Tsuneo !