Where is the table for HID Global Items?

Question

I looked through the HID Usage Tables, and I can understand which codes correspond to which in a report descriptor, for example a mouse or a keyboard. But I couldn't find anything both in the Usage Tables nor the HID Spec supplement that says for example, 0x06 is Usage Page, 0xA1 is the start of a Collection, and 0xC0 is the end of a collection.

Where is the document that shows all the hex codes for the titles themselves?

Answer 1

The information you seek is in the documents you have cited in your question - although I have to admit that they are quite difficult to understand. To help with HID report descriptor decoding I have written a program to do that - see https://github.com/abend0c1/hidrdd (or https://codeberg.org/abend0c1/hidrdd if you have philosophical issues with github).

You can get that program to list a summary of all the report descriptor codes by issuing:

rexx rd.rex --codes

...which results in:

Table of item codes in hexadecimal. The item code varies depending on the
length of the subsequent item data field as follows:

                              Data Field Length
Item                           0    1    2    4   Comment
---------------------------   --   --   --   --   -----------------------------
(MAIN)   INPUT                80   81   82   83   Defines input to the host device
(MAIN)   OUTPUT               90   91   92   93   Defines output from the host device
(MAIN)   COLLECTION           A0   A1   A2   A3   See collection types below
(MAIN)   FEATURE              B0   B1   B2   B3   Defines data to or from the host device
(MAIN)   END_COLLECTION       C0                  Item data field is not supported
(GLOBAL) USAGE_PAGE                05   06   07   USAGE_PAGE 00 is invalid
(GLOBAL) LOGICAL_MINIMUM      14   15   16   17
(GLOBAL) LOGICAL_MAXIMUM      24   25   26   27
(GLOBAL) PHYSICAL_MINIMUM     34   35   36   37
(GLOBAL) PHYSICAL_MAXIMUM     44   45   46   47
(GLOBAL) UNIT_EXPONENT        54   55   56   57
(GLOBAL) UNIT                 64   65   66   67
(GLOBAL) REPORT_ID                 85   86   87   REPORT_ID=0 is reserved
(GLOBAL) REPORT_SIZE               75   76   77   REPORT_SIZE=0 is invalid
(GLOBAL) REPORT_COUNT         94   95   96   97   REPORT_COUNT=0 is not useful
(GLOBAL) PUSH                 A4                  Item data field is not supported
(GLOBAL) POP                  B4                  Item data field is not supported
(LOCAL)  USAGE                08   09   0A   0B
(LOCAL)  USAGE_MINIMUM        18   19   1A   1B
(LOCAL)  USAGE_MAXIMUM        28   29   2A   2B
(LOCAL)  DESIGNATOR_INDEX     38   39   3A   3B
(LOCAL)  DESIGNATOR_MINIMUM   48   49   4A   4B
(LOCAL)  DESIGNATOR_MAXIMUM   58   59   5A   5B
(LOCAL)  STRING_INDEX         78   79   7A   7B
(LOCAL)  STRING_MINIMUM       88   89   8A   8B
(LOCAL)  STRING_MAXIMUM       98   99   9A   9B
(LOCAL)  DELIMITER            A8   A9   AA   AB

COLLECTION item codes are as follows:

Physical Collection:          A1 00               Alternatively: A0
Application Collection:       A1 01               Alternatively: A2 01 00, or A3 01 00 00 00
Logical Collection:           A1 02
Report Collection:            A1 03
Named Array Collection:       A1 04               Must contain only Selector usages
Usage Switch Collection:      A1 05
Usage Modifier Collection:    A1 06

Hopefully that is of some help to you.