USB HID规范说明
每个顶级集合必须是应用程序集合，而报告可能不是 跨越多个顶级集合。
但是，USB HID报告描述符工具中提供的示例之一，即显示示例，具有逻辑类型的顶级集合，没有应用程序集合：
svn commit这是允许的吗？
答案 0 :(得分：2)
不，不允许。
给出的示例似乎与＆＃34;附录A.8带有显示器的设备＆＃34;中的示例非常相似。在HID Usage Tables v1.12 specification 确实定义了顶级应用程序集合。
我说你发布的示例可能有一些转录错误 - 特别是因为选择的顶级用法（0x00140001）具有CA的使用类型，因此旨在用于Application Collection项而不是Logical集合（参见“使用表”文档的第109页）。
第一个逻辑集合应更改为：
0xa1, 0x01, // COLLECTION (Application)
然后将解析它（尽管由于原始示例中省略了部分而导致位对齐问题）：
//--------------------------------------------------------------------------------
// Decoded Application Collection
//--------------------------------------------------------------------------------
/*
05 14 (GLOBAL) USAGE_PAGE 0x0014 Alphanumeric Display Page
09 01 (LOCAL) USAGE 0x00140001 Alphanumeric Display (CA=Application Collection)
15 00 (GLOBAL) LOGICAL_MINIMUM 0x00 (0) <-- Redundant: LOGICAL_MINIMUM is already 0 <-- Info: Consider replacing 15 00 with 14
A1 01 (MAIN) COLLECTION 0x00000001 Application (Usage=0x00140001: Page=Alphanumeric Display Page, Usage=Alphanumeric Display, Type=CA)
09 20 (LOCAL) USAGE 0x00140020 Display Attributes Report (CL=Logical Collection)
A1 02 (MAIN) COLLECTION 0x00000002 Logical (Usage=0x00140020: Page=Alphanumeric Display Page, Usage=Display Attributes Report, Type=CL)
09 35 (LOCAL) USAGE 0x00140035 Rows (SV=Static Value)
09 36 (LOCAL) USAGE 0x00140036 Columns (SV=Static Value)
09 3D (LOCAL) USAGE 0x0014003D Character Width (SV=Static Value)
09 3E (LOCAL) USAGE 0x0014003E Character Height (SV=Static Value)
85 01 (GLOBAL) REPORT_ID 0x01 (1)
25 1F (GLOBAL) LOGICAL_MAXIMUM 0x1F (31)
75 05 (GLOBAL) REPORT_SIZE 0x05 (5) Number of bits per field
95 04 (GLOBAL) REPORT_COUNT 0x04 (4) Number of fields
B1 03 (MAIN) FEATURE 0x00000003 (4 fields x 5 bits) 1=Constant 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 0=Bitmap
75 01 (GLOBAL) REPORT_SIZE 0x01 (1) Number of bits per field
95 03 (GLOBAL) REPORT_COUNT 0x03 (3) Number of fields
25 01 (GLOBAL) LOGICAL_MAXIMUM 0x01 (1)
09 21 (LOCAL) USAGE 0x00140021 ASCII Character Set (SF=Static Flag)
09 22 (LOCAL) USAGE 0x00140022 Data Read Back (SF=Static Flag)
09 29 (LOCAL) USAGE 0x00140029 Vertical Scroll (SFDF=Static Flag or Dynamic Flag)
B1 03 (MAIN) FEATURE 0x00000003 (3 fields x 1 bit) 1=Constant 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 0=Bitmap
95 03 (GLOBAL) REPORT_COUNT 0x03 (3) Number of fields <-- Redundant: REPORT_COUNT is already 3
B1 03 (MAIN) FEATURE 0x00000003 (3 fields x 1 bit) 1=Constant 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 0=Bitmap
C0 (MAIN) END_COLLECTION Logical
75 08 (GLOBAL) REPORT_SIZE 0x08 (8) Number of bits per field
95 01 (GLOBAL) REPORT_COUNT 0x01 (1) Number of fields
25 02 (GLOBAL) LOGICAL_MAXIMUM 0x02 (2)
09 2D (LOCAL) USAGE 0x0014002D Display Status (CL=Logical Collection)
A1 02 (MAIN) COLLECTION 0x00000002 Logical (Usage=0x0014002D: Page=Alphanumeric Display Page, Usage=Display Status, Type=CL)
09 2E (LOCAL) USAGE 0x0014002E Stat Not Ready (Sel=Selector)
09 2F (LOCAL) USAGE 0x0014002F Stat Ready (Sel=Selector)
09 30 (LOCAL) USAGE 0x00140030 Err Not a loadable character (Sel=Selector)
81 40 (MAIN) INPUT 0x00000040 (1 field x 8 bits) 0=Data 0=Array 0=Absolute
C0 (MAIN) END_COLLECTION Logical
09 32 (LOCAL) USAGE 0x00140032 Cursor Position Report (CL=Logical Collection)
A1 02 (MAIN) COLLECTION 0x00000002 Logical (Usage=0x00140032: Page=Alphanumeric Display Page, Usage=Cursor Position Report, Type=CL)
85 02 (GLOBAL) REPORT_ID 0x02 (2)
75 04 (GLOBAL) REPORT_SIZE 0x04 (4) Number of bits per field
95 01 (GLOBAL) REPORT_COUNT 0x01 (1) Number of fields <-- Redundant: REPORT_COUNT is already 1
25 0F (GLOBAL) LOGICAL_MAXIMUM 0x0F (15)
09 34 (LOCAL) USAGE 0x00140034 Column (DV=Dynamic Value)
B1 22 (MAIN) FEATURE 0x00000022 (1 field x 4 bits) 0=Data 1=Variable 0=Absolute 0=NoWrap 0=Linear 1=NoPrefState 0=NoNull 0=NonVolatile 0=Bitmap
25 01 (GLOBAL) LOGICAL_MAXIMUM 0x01 (1)
09 33 (LOCAL) USAGE 0x00140033 Row (DV=Dynamic Value)
B1 22 (MAIN) FEATURE 0x00000022 (1 field x 4 bits) 0=Data 1=Variable 0=Absolute 0=NoWrap 0=Linear 1=NoPrefState 0=NoNull 0=NonVolatile 0=Bitmap
C0 (MAIN) END_COLLECTION Logical
09 2B (LOCAL) USAGE 0x0014002B Character Report (CL=Logical Collection)
A1 02 (MAIN) COLLECTION 0x00000002 Logical (Usage=0x0014002B: Page=Alphanumeric Display Page, Usage=Character Report, Type=CL)
85 03 (GLOBAL) REPORT_ID 0x03 (3)
75 08 (GLOBAL) REPORT_SIZE 0x08 (8) Number of bits per field
95 04 (GLOBAL) REPORT_COUNT 0x04 (4) Number of fields
25 7E (GLOBAL) LOGICAL_MAXIMUM 0x7E (126)
09 2C (LOCAL) USAGE 0x0014002C Display Data (DV=Dynamic Value)
B2 0201 (MAIN) FEATURE 0x00000102 (4 fields x 8 bits) 0=Data 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 1=Buffer
C0 (MAIN) END_COLLECTION Logical
85 04 (GLOBAL) REPORT_ID 0x04 (4)
09 3B (LOCAL) USAGE 0x0014003B Font Report (CL=Logical Collection)
A1 02 (MAIN) COLLECTION 0x00000002 Logical (Usage=0x0014003B: Page=Alphanumeric Display Page, Usage=Font Report, Type=CL)
15 00 (GLOBAL) LOGICAL_MINIMUM 0x00 (0) <-- Redundant: LOGICAL_MINIMUM is already 0 <-- Info: Consider replacing 15 00 with 14
25 7E (GLOBAL) LOGICAL_MAXIMUM 0x7E (126) <-- Redundant: LOGICAL_MAXIMUM is already 126
75 08 (GLOBAL) REPORT_SIZE 0x08 (8) Number of bits per field <-- Redundant: REPORT_SIZE is already 8
95 01 (GLOBAL) REPORT_COUNT 0x01 (1) Number of fields
09 2C (LOCAL) USAGE 0x0014002C Display Data (DV=Dynamic Value)
91 02 (MAIN) OUTPUT 0x00000002 (1 field x 8 bits) 0=Data 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 0=Bitmap
95 05 (GLOBAL) REPORT_COUNT 0x05 (5) Number of fields
09 3C (LOCAL) USAGE 0x0014003C Font Data (BB=Buffered Bytes)
92 0201 (MAIN) OUTPUT 0x00000102 (5 fields x 8 bits) 0=Data 1=Variable 0=Absolute 0=NoWrap 0=Linear 0=PrefState 0=NoNull 0=NonVolatile 1=Buffer
C0 (MAIN) END_COLLECTION Logical
C0 (MAIN) END_COLLECTION Application
*/
//--------------------------------------------------------------------------------
// Alphanumeric Display Page featureReport 01 (Device <-> Host)
//--------------------------------------------------------------------------------
typedef struct
{
uint8_t reportId; // Report ID = 0x01 (1)
// Collection: AlphanumericDisplay DisplayAttributesReport
uint8_t AD_AlphanumericDisplayDisplayAttributesReportRows : 5; // Usage 0x00140035: Rows, Value = 0 to 31
uint8_t AD_AlphanumericDisplayDisplayAttributesReportColumns : 5; // Usage 0x00140036: Columns, Value = 0 to 31
uint8_t AD_AlphanumericDisplayDisplayAttributesReportCharacterWidth : 5; // Usage 0x0014003D: Character Width, Value = 0 to 31
uint8_t AD_AlphanumericDisplayDisplayAttributesReportCharacterHeight : 5; // Usage 0x0014003E: Character Height, Value = 0 to 31
uint8_t AD_AlphanumericDisplayDisplayAttributesReportAsciiCharacterSet : 1; // Usage 0x00140021: ASCII Character Set, Value = 0 to 1
uint8_t AD_AlphanumericDisplayDisplayAttributesReportDataReadBack : 1; // Usage 0x00140022: Data Read Back, Value = 0 to 1
uint8_t AD_AlphanumericDisplayDisplayAttributesReportVerticalScroll : 1; // Usage 0x00140029: Vertical Scroll, Value = 0 to 1
uint8_t : 1; // Pad
uint8_t : 1; // Pad
uint8_t : 1; // Pad
} featureReport01_t;
//--------------------------------------------------------------------------------
// Alphanumeric Display Page featureReport 02 (Device <-> Host)
//--------------------------------------------------------------------------------
typedef struct
{
uint8_t reportId; // Report ID = 0x02 (2)
// Collection: AlphanumericDisplay CursorPositionReport
uint8_t AD_AlphanumericDisplayCursorPositionReportColumn : 4; // Usage 0x00140034: Column, Value = 0 to 15
uint8_t AD_AlphanumericDisplayCursorPositionReportRow : 4; // Usage 0x00140033: Row, Value = 0 to 1
} featureReport02_t;
//--------------------------------------------------------------------------------
// Alphanumeric Display Page featureReport 03 (Device <-> Host)
//--------------------------------------------------------------------------------
typedef struct
{
uint8_t reportId; // Report ID = 0x03 (3)
// Collection: AlphanumericDisplay CharacterReport
uint8_t AD_AlphanumericDisplayCharacterReportDisplayData[4]; // Usage 0x0014002C: Display Data, Value = 0 to 126
} featureReport03_t;
//--------------------------------------------------------------------------------
// Alphanumeric Display Page inputReport 01 (Device --> Host)
//--------------------------------------------------------------------------------
typedef struct
{
uint8_t reportId; // Report ID = 0x01 (1)
// Collection: AlphanumericDisplay DisplayStatus
uint8_t AD_AlphanumericDisplayDisplayStatus; // Value = 0 to 2
// Value 0 = Usage 0x0014002E: Stat Not Ready
// Value 1 = Usage 0x0014002F: Stat Ready
// Value 2 = Usage 0x00140030: Err Not a loadable character
} inputReport01_t;
//--------------------------------------------------------------------------------
// Alphanumeric Display Page outputReport 04 (Device <-- Host)
//--------------------------------------------------------------------------------
typedef struct
{
uint8_t reportId; // Report ID = 0x04 (4)
// Collection: AlphanumericDisplay FontReport
uint8_t AD_AlphanumericDisplayFontReportDisplayData; // Usage 0x0014002C: Display Data, Value = 0 to 126
uint8_t AD_AlphanumericDisplayFontReportFontData[5]; // Usage 0x0014003C: Font Data, Value = 0 to 126
} outputReport04_t;