Files added to Host CDC projects:
- usb-host-cdc.h
- usb-host-hub-cdc.h
- usb-host-cdc.c
- usb-host-cdc-acm.c
Application Programming Interfaces (APIs) provided:
USB_HOST_CDC_Open
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_CDC_Open Opens the specified Communication Device Class (CDC) device. Once opened, the application will access the device by the returned 'handle'. |
Host CDC Object ID | CDC Handle |
Example of opening a CDC Device:
USB_HOST_CDC_HANDLE cdcHostHandle;
USB_HOST_CDC_OBJ cdcObj;
. . .
cdcHostHandle = USB_HOST_CDC_Open(cdcObj);
if(cdcHostHandle != USB_HOST_CDC_HANDLE_INVALID)
{
/* The driver was opened successfully. Set the event handler
* and then go to the next state. */
}
. . .
USB_HOST_CDC_Close
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_CDC_Close Closes the association between the application entity that opened the device and the device. The driver handle becomes invalid. |
CDC Handle | Void |
Example of closing a CDC Device:
USB_HOST_CDC_HANDLE cdcHostHandle;
. . .
USB_HOST_CDC_Open(cdHostHandle);
. . .
USB_HOST_CDC_AttachEventHandlerSet
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_AttachEventHandlerSet Sets the function to be called when the enumeration process attaches the device. |
Event Handler Context |
USB_HOST_CDC_RESULT |
Example of setting the Attach Event handler:
USB_HOST_CDC_OBJ cdcObj;
. . .
void MyAttachFunction( USB_HOST_CDC_OBJ cdcObj, uintptr_t context);
{ … }
. . .
USB_HOST_CDC_AttachEventHandlerSet(MyAttachFunction, (uintptr_t) 0);
USB_HOST_CDC_EventHandlerSet
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_EventHandlerSet Registers the CDC Host Client driver event handler for the specific device. This event handler is called by the driver in response to data transfers by the client device. |
Handle Event Handler Context |
USB_HOST_CDC_RESULT |
Example of setting the Event handler:
USB_HOST_CDC_HANDLE cdcHostHandle;
USB_HOST_CDC_OBJ cdcObj;
. . .
cdcHostHandle = USB_HOST_CDC_Open(cdcObj);
if(cdcHostHandle != USB_HOST_CDC_HANDLE_INVALID)
{
/* The driver was opened successfully. Set the event handler */
USB_HOST_CDC_EventHandlerSet(cdcHostHandle, MyEventHandler, (uintptr_t)0);
}
. . .
USB_HOST_CDC_Write
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_CDC_Write Writes data to the specified device. |
Handle &Transfer Handle &Data length |
USB_HOST_CDC_RESULT |
Example of writing to a CDC Device:
USB_HOST_CDC_HANDLE cdcHostHandle;
USB_HOST_CDC_RESULT result;
char prompt[] = "Good Morning" ;
. . .
result = USB_HOST_CDC_Write(cdcHostHandle, NULL, prompt, 13);
if(result == USB_HOST_CDC_RESULT_SUCCESS)
{
// transmit successfully initiated
}
. . .
USB_HOST_CDC_Read
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_CDC_Read Reads data from the specified device. |
Handle &Transfer Handle &Data Length |
USB_HOST_CDC_RESULT |
Example of reading from a CDC Device:
USB_HOST_CDC_HANDLE cdcHostHandle;
USB_HOST_CDC_RESULT result;
char MyInputBuffer[0x20] ;
. . .
result = USB_HOST_CDC_Read(cdcHostHandle, NULL, MyInputBuffer, 0x20);
if(result == USB_HOST_CDC_EVENT_READ_COMPLETE)
{
// data was successfully received
}
. . .
USB_HOST_CDC_SerialStateNotificationGet
| Description | Inputs | Returns |
|---|---|---|
| USB_HOST_SerialNotifiationGet Requests Serial State notification from the attached device. If the request was accepted, Transfer Handle will contain a valid transfer handle, else it will contain USB_HOST_CDC_TRANSFER_HANDLE_INVALID. |
Handle &Transfer Handle &Serial State |
USB_HOST_CDC_RESULT |
Example of setting the getting the Serial State:
USB_CDC_SERIAL_STATE state;
USB_HOST_CDC_HANDLE cdcHostHandle;
. . .
USB_HOST_CDC_SerialStateNotificationGet(cdcHostHandle, &transferhandle, state);