Cdc

Detailed Description

Implements USB Communication Device Class (CDC).

CDC implementation.

The source code of the CDC implementation resides in kits/common/drivers/cdc.c and cdc.h. This driver implements a basic USB to RS232 bridge.

CDC device configuration options.

This section contains a description of the configuration options for the driver. The options are #define's which are expected to be found in the application "usbconfig.h" header file. The values shown below are from the Giant Gecko DK3750 CDC example.

// USB interface numbers. Interfaces are numbered from zero to one less than
// the number of concurrent interfaces supported by the configuration. A CDC
// device is by itself a composite device and has two interfaces.
// The interface numbers must be 0 and 1 for a standalone CDC device, for a
// composite device which includes a CDC interface it must not be in conflict
// with other device interfaces.
#define CDC_CTRL_INTERFACE_NO ( 0 )
#define CDC_DATA_INTERFACE_NO ( 1 )

// Endpoint address for CDC data reception.
#define CDC_EP_DATA_OUT ( 0x01 )

// Endpoint address for CDC data transmission.
#define CDC_EP_DATA_IN ( 0x81 )

// Endpoint address for the notification endpoint (not used).
#define CDC_EP_NOTIFY ( 0x82 )

// Timer id, see USBTIMER in the USB device stack documentation.
// The CDC driver has a Rx timeout functionality which require a timer.
#define CDC_TIMER_ID ( 0 )

// DMA related macros, select DMA channels and DMA request signals.
#define CDC_UART_TX_DMA_CHANNEL   ( 0 )
#define CDC_UART_RX_DMA_CHANNEL   ( 1 )
#define CDC_TX_DMA_SIGNAL         DMAREQ_UART1_TXBL
#define CDC_RX_DMA_SIGNAL         DMAREQ_UART1_RXDATAV

// UART/USART selection macros.
#define CDC_UART                  UART1
#define CDC_UART_CLOCK            cmuClock_UART1
#define CDC_UART_ROUTE            ( UART_ROUTE_RXPEN | UART_ROUTE_TXPEN | \
                                    UART_ROUTE_LOCATION_LOC2 )
#define CDC_UART_TX_PORT          gpioPortB
#define CDC_UART_TX_PIN           9
#define CDC_UART_RX_PORT          gpioPortB
#define CDC_UART_RX_PIN           10

// Activate the RS232 switch on DK's.
#define CDC_ENABLE_DK_UART_SWITCH() BSP_PeripheralAccess(BSP_RS232_UART, true)

// No RS232 switch on STK's. Leave the definition "empty".
#define CDC_ENABLE_DK_UART_SWITCH()

Functions
void	CDC_Init (void)
	CDC device initialization.
int	CDC_SetupCmd (const USB_Setup_TypeDef *setup)
	Handle USB setup commands. Implements CDC class specific commands. More...
void	CDC_StateChangeEvent (USBD_State_TypeDef oldState, USBD_State_TypeDef newState)
	Callback function called each time the USB device state is changed. Starts CDC operation when device has been configured by USB host. More...

Function Documentation

int CDC_SetupCmd

(

const USB_Setup_TypeDef *

setup

)

Handle USB setup commands. Implements CDC class specific commands.

Parameters

[in]

setup

Pointer to the setup packet received.

Returns

USB_STATUS_OK if command accepted. USB_STATUS_REQ_UNHANDLED when command is unknown, the USB device stack will handle the request.

Definition at line 183 of file cdc.c.

References USB_Setup_TypeDef::bRequest, USB_Setup_TypeDef::Direction, USB_Setup_TypeDef::Recipient, USB_Setup_TypeDef::Type, USB_CDC_GETLINECODING, USB_CDC_SETCTRLLINESTATE, USB_CDC_SETLINECODING, USB_SETUP_DIR_IN, USB_SETUP_RECIPIENT_INTERFACE, USB_SETUP_TYPE_CLASS, USB_STATUS_OK, USB_STATUS_REQ_UNHANDLED, USBD_Read(), USBD_Write(), USB_Setup_TypeDef::wIndex, USB_Setup_TypeDef::wLength, and USB_Setup_TypeDef::wValue.

void CDC_StateChangeEvent	(	USBD_State_TypeDef	oldState,
		USBD_State_TypeDef	newState
	)

Callback function called each time the USB device state is changed. Starts CDC operation when device has been configured by USB host.

Parameters

[in]	oldState	The device state the device has just left.
[in]	newState	The new device state.

Definition at line 241 of file cdc.c.

References DMA, DMA_ActivateBasic(), USBD_Read(), USBD_STATE_CONFIGURED, USBD_STATE_SUSPENDED, USBTIMER_Start(), and USBTIMER_Stop().