USB Device Interface (UDI) for Mass Storage Class (MSC)

USB Device Interface (UDI) for Mass Storage Class (MSC) provides an interface for the configuration and management of USB MSC storage device.

The outline of this documentation is as follows:

• API Overview
• Quick Start Guide for USB Device Mass Storage Module (UDI MSC)
• Configuration File Examples

For more details for Atmel® Software Framework (ASF) USB Device Stack, refer to following application notes:

• AVR4900: ASF - USB Device Stack
• AVR4920: ASF - USB Device Stack - Compliance and Performance Figures
• AVR4921: ASF - USB Device Stack Differences between ASF V1 and V2

API Overview

Data Structures
struct	udi_msc_desc_t
	Interface descriptor structure for MSC. More...

Functions
bool	udi_msc_process_trans (void)
	Process the background read/write commands. More...
bool	udi_msc_trans_block (bool b_read, uint8_t *block, iram_size_t block_size, void(*callback)(udd_ep_status_t status, iram_size_t n, udd_ep_id_t ep))
	Transfers data to/from USB MSC endpoints. More...

UDI MSC Interface for UDC
UDC_DESC_STORAGE udi_api_t	udi_api_msc
	Global structure which contains standard UDI interface for UDC. More...

USB Interface Descriptors
The following structures provide predefined USB interface descriptors. It must be used to define the final USB descriptors.
#define	UDI_MSC_STRING_ID   0
	By default no string is associated to this interface. More...
#define	UDI_MSC_EPS_SIZE_FS   64
	MSC endpoints size for full speed. More...
#define	UDI_MSC_EPS_SIZE_HS   512
	MSC endpoints size for high speed. More...
#define	UDI_MSC_DESC
	Content of MSC interface descriptor for all speeds. More...
#define	UDI_MSC_DESC_FS
	Content of MSC interface descriptor for full speed only. More...
#define	UDI_MSC_DESC_HS
	Content of MSC interface descriptor for high speed only. More...

#define UDI_MSC_DESC

Value:

.iface.bLength             = sizeof(usb_iface_desc_t),\
   .iface.bDescriptorType     = USB_DT_INTERFACE,\
   .iface.bInterfaceNumber    = UDI_MSC_IFACE_NUMBER,\
   .iface.bAlternateSetting   = 0,\
   .iface.bNumEndpoints       = 2,\
   .iface.bInterfaceClass     = MSC_CLASS,\
   .iface.bInterfaceSubClass  = MSC_SUBCLASS_TRANSPARENT,\
   .iface.bInterfaceProtocol  = MSC_PROTOCOL_BULK,\
   .iface.iInterface          = UDI_MSC_STRING_ID,\
   .ep_in.bLength             = sizeof(usb_ep_desc_t),\
   .ep_in.bDescriptorType     = USB_DT_ENDPOINT,\
   .ep_in.bEndpointAddress    = UDI_MSC_EP_IN,\
   .ep_in.bmAttributes        = USB_EP_TYPE_BULK,\
   .ep_in.bInterval           = 0,\
   .ep_out.bLength            = sizeof(usb_ep_desc_t),\
   .ep_out.bDescriptorType    = USB_DT_ENDPOINT,\
   .ep_out.bEndpointAddress   = UDI_MSC_EP_OUT,\
   .ep_out.bmAttributes       = USB_EP_TYPE_BULK,\
   .ep_out.bInterval          = 0,

Content of MSC interface descriptor for all speeds.

#define UDI_MSC_DESC_FS

Value:

{\
   UDI_MSC_DESC \
   .ep_in.wMaxPacketSize      = LE16(UDI_MSC_EPS_SIZE_FS),\
   .ep_out.wMaxPacketSize     = LE16(UDI_MSC_EPS_SIZE_FS),\
   }

Content of MSC interface descriptor for full speed only.

#define UDI_MSC_DESC_HS

Value:

{\
   UDI_MSC_DESC \
   .ep_in.wMaxPacketSize      = LE16(UDI_MSC_EPS_SIZE_HS),\
   .ep_out.wMaxPacketSize     = LE16(UDI_MSC_EPS_SIZE_HS),\
   }

Content of MSC interface descriptor for high speed only.

#define UDI_MSC_EPS_SIZE_FS   64

MSC endpoints size for full speed.

#define UDI_MSC_EPS_SIZE_HS   512

MSC endpoints size for high speed.

#define UDI_MSC_STRING_ID   0

By default no string is associated to this interface.

bool udi_msc_process_trans

(

void

)

Process the background read/write commands.

Routine called by the main loop.

bool udi_msc_trans_block	(	bool	b_read,
		uint8_t *	block,
		iram_size_t	block_size,
		void(*)(udd_ep_status_t status, iram_size_t n, udd_ep_id_t ep)	callback
	)

Transfers data to/from USB MSC endpoints.

Parameters

[in]	b_read	Memory to USB, if true
[in,out]	block	Buffer on Internal RAM to send or fill
[in]	block_size	Buffer size to send or fill
[in]	callback	Function to call at the end of transfer. If NULL then the routine exit when transfer is finish.

Returns

1 if function was successfully done, otherwise 0.

UDC_DESC_STORAGE udi_api_t udi_api_msc

Global structure which contains standard UDI interface for UDC.