Descriptors.c File Reference

#include "Descriptors.h"

Functions
uint16_t	CALLBACK_USB_GetDescriptor (const uint16_t wValue, const uint8_t wIndex, const void **const DescriptorAddress)

Variables
const USB_Descriptor_Device_t	DeviceDescriptor
const USB_Descriptor_Configuration_t	ConfigurationDescriptor

Detailed Description

USB Device Descriptors, for library use when in USB device mode. Descriptors are special computer-readable structures which the host requests upon device enumeration, to determine the device's capabilities and functions.

Function Documentation

uint16_t CALLBACK_USB_GetDescriptor	(	const uint16_t	wValue,
		const uint8_t	wIndex,
		const void **const	DescriptorAddress
	)

This function is called by the library when in device mode, and must be overridden (see library "USB Descriptors" documentation) by the application code so that the address and size of a requested descriptor can be given to the USB library. When the device receives a Get Descriptor request on the control endpoint, this function is called so that the descriptor details can be passed back and the appropriate descriptor sent back to the USB host.

Variable Documentation

const USB_Descriptor_Configuration_t ConfigurationDescriptor

Configuration descriptor structure. This descriptor, located in FLASH memory, describes the usage of the device in one of its supported configurations, including information about any device interfaces and endpoints. The descriptor is read out by the USB host during the enumeration process when selecting a configuration so that the host may correctly communicate with the USB device.

const USB_Descriptor_Device_t DeviceDescriptor

Initial value:

=
{
    .Header                 = {.Size = sizeof(USB_Descriptor_Device_t), .Type = DTYPE_Device},

    .USBSpecification       = VERSION_BCD(01.10),
    .Class                  = USB_CSCP_NoDeviceClass,
    .SubClass               = USB_CSCP_NoDeviceSubclass,
    .Protocol               = USB_CSCP_NoDeviceProtocol,

    .Endpoint0Size          = FIXED_CONTROL_ENDPOINT_SIZE,

    .VendorID               = 0x03EB,
    .ProductID              = 0x2045,
    .ReleaseNumber          = VERSION_BCD(00.01),

    .ManufacturerStrIndex   = NO_DESCRIPTOR,
    .ProductStrIndex        = NO_DESCRIPTOR,
    .SerialNumStrIndex      = NO_DESCRIPTOR,

    .NumberOfConfigurations = FIXED_NUM_CONFIGURATIONS
}

Device descriptor structure. This descriptor, located in SRAM memory, describes the overall device characteristics, including the supported USB version, control endpoint size and the number of device configurations. The descriptor is read out by the USB host when the enumeration process begins.