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Contains APIs related to CDC (Virtual COMport) device class.
Functions | |
uint8_t | USBCDC_sendData (const uint8_t *data, uint16_t size, uint8_t intfNum) |
uint8_t | USBCDC_abortSend (uint16_t *size, uint8_t intfNum) |
uint8_t | USBCDC_receiveData (uint8_t *data, uint16_t size, uint8_t intfNum) |
uint8_t | USBCDC_abortReceive (uint16_t *size, uint8_t intfNum) |
uint8_t | USBCDC_rejectData (uint8_t intfNum) |
uint8_t | USBCDC_getInterfaceStatus (uint8_t intfNum, uint16_t *bytesSent, uint16_t *bytesReceived) |
uint8_t | USBCDC_getBytesInUSBBuffer (uint8_t intfNum) |
uint8_t USBCDC_sendData | ( | const uint8_t * | data, |
uint16_t | size, | ||
uint8_t | intfNum | ||
) |
Begins a Send Operation to the USB Host.
*data | is an array of data to be sent. |
size | is the number of bytes to be sent, starting from address data. |
intfNum | selects which data should be transmitted over. |
Initiates sending of a user buffer over CDC interface intfNum, of size size and starting at address data. If size is larger than the packet size, the function handles all packetization and buffer management. size has no inherent upper limit (beyond being a 16-bit value).
In most cases where a send operation is successfully started, the function will return USBCDC_SEND_STARTED. A send operation is said to be underway. At some point, either before or after the function returns, the send operation will complete, barring any events that would preclude it. (Even if the operation completes before the function returns, the return code will still be USBCDC_SEND_STARTED.) If the bus is not connected when the function is called, the function returns USBCDC_BUS_NOT_AVAILABLE, and no operation is begun. If size is 0, the function returns USBCDC_GENERAL_ERROR. If a previous send operation is already underway for this data interface, the function returns with USBCDC_INTERFACE_BUSY_ERROR.
USB includes low-level mechanisms that ensure valid transmission of data.
See Sec. 7.2 of "Programmer's Guide: MSP430 USB API Stack for CDC/PHDC/HID/MSC" for a detailed discussion of send operations.
Referenced by USBCDC_sendDataAndWaitTillDone(), and USBCDC_sendDataInBackground().
uint8_t USBCDC_abortSend | ( | uint16_t * | size, |
uint8_t | intfNum | ||
) |
Aborts an Active Send Operation.
size | is the number of bytes that were sent prior to the abort action. |
intfNum | is the data interface for which the send should be aborted. |
Aborts an active send operation on data interface intfNum. Returns the number of bytes that were sent prior to the abort, in size.
An application may choose to call this function if sending failed, due to factors such as:
uint8_t USBCDC_receiveData | ( | uint8_t * | data, |
uint16_t | size, | ||
uint8_t | intfNum | ||
) |
Begins a Receive Operation from the USB Host.
*data | is an array to contain the data received. |
size | is the number of bytes to be received. |
intfNum | is which data interface to receive from. |
Receives size bytes over CDC interface intfNum into memory starting at address data. size has no inherent upper limit (beyond being a 16-bit value).
The function may return with USBCDC_RECEIVE_STARTED, indicating that a receive operation is underway. The operation completes when size bytes are received. The application should ensure that the data memory buffer be available during the whole of the receive operation.
The function may also return with USBCDC_RECEIVE_COMPLETED. This means that the receive operation was complete by the time the function returned.
If the bus is not connected when the function is called, the function returns USBCDC_BUS_NOT_AVAILABLE, and no operation is begun. If size is 0, the function returns USBCDC_GENERAL_ERROR. If a previous receive operation is already underway for this data interface, the function returns USBCDC_INTERFACE_BUSY_ERROR.
USB includes low-level mechanisms that ensure valid transmission of data.
See Sec. 7.2 of "Programmer's Guide: MSP430 USB API Stack for CDC/PHDC/HID/MSC" for a detailed discussion of receive operations.
Referenced by USBCDC_receiveDataInBuffer().
uint8_t USBCDC_abortReceive | ( | uint16_t * | size, |
uint8_t | intfNum | ||
) |
Aborts an Active Receive Operation.
*size | is the number of bytes that were received and are waiting at the assigned address. |
intfNum | is the data interface for which the send should be aborted. |
Aborts an active receive operation on CDC interface intfNum. Returns the number of bytes that were received and transferred to the data location established for this receive operation. The data moved to the buffer up to that time remains valid.
An application may choose to call this function if it decides it no longer wants to receive data from the USB host. It should be noted that if a continuous stream of data is being received from the host, aborting the operation is akin to pressing a "pause" button; the host will be NAK'ed until another receive operation is opened.
See Sec. 7.2 of "Programmer's Guide: MSP430 USB API Stack for CDC/PHDC/HID/MSC" for a detailed discussion of receive operations.
uint8_t USBCDC_rejectData | ( | uint8_t | intfNum) |
Rejects the Data Received from the Host.
This function rejects data that has been received from the host, for interface inftNum, that does not have an active receive operation underway. It resides in the USB endpoint buffer and blocks further data until a receive operation is opened, or until rejected. When this function is called, the buffer for this interface is purged, and the data lost. This frees the USB path to resume communication.
See Sec. 7.2 of "Programmer's Guide: MSP430 USB API Stack for CDC/PHDC/HID/MSC" for a detailed discussion of receive operations.
uint8_t USBCDC_getInterfaceStatus | ( | uint8_t | intfNum, |
uint16_t * | bytesSent, | ||
uint16_t * | bytesReceived | ||
) |
Indicates the Status of the CDC Interface.
intfNum | is the interface number for which status is being retrieved. |
bytesSent | If a send operation is underway, the number of bytes that send have been transferred to the host is returned in this location. If no operation is underway, this returns zero. |
bytesReceived | If a receive operation is underway, the number of bytes that have been transferred to the assigned memory location is returned in this location. If no receive operation is underway, this returns zero. |
Indicates the status of the CDC interface intfNum. If a send operation is active for this interface, the function also returns the number of bytes that have been transmitted to the host. If a receive operation is active for this interface, the function also returns the number of bytes that have been received from the host and are waiting at the assigned address.
Because multiple flags can be returned, the possible values can be masked together - for example, USBCDC_WAITING_FOR_SEND + USBCDC_DATA_WAITING.
Referenced by USBCDC_sendDataAndWaitTillDone(), and USBCDC_sendDataInBackground().
uint8_t USBCDC_getBytesInUSBBuffer | ( | uint8_t | intfNum) |
Gives the Number of Bytes in the USB Endpoint Buffer.
intfNum | is the data interface whose buffer is to be checked. |
Returns the number of bytes waiting in the USB endpoint buffer for intfNum. A non-zero value generally means that no receive operation is open by which these bytes can be copied to a user buffer. If the value is non-zero, the application should either open a receive operation so that the data can be moved out of the endpoint buffer, or the data should be rejected (USBCDC_rejectData()).
Referenced by USBCDC_receiveDataInBuffer().