2.3.6 PHY_TxFrame Function

C

PHY_Retval_t PHY_TxFrame(PHY_FrameInfo_t *txFrame, PHY_CSMAMode_t csmaMode,
bool performFrameRetry)

Summary

Request to PHY to transmit frame

Description

This function is called by the upper layer (MAC/Application) to deliver a frame to the PHY to be transmitted by the transceiver.

Precondition

PHY_Init() should have been called before calling this function

Parameters


Param	Description	Comments
txFrame	Pointer to the PHY_FrameInfo_t structure or to frame array to be transmitted
	txFrame->mpdu	Pointer to the PHY Payload. mpdu should hold the length of the payload(N) + 1 (for length field length)
	txFrame->mpdu	Hold the phyPayload
csmaMode	Indicates mode of csma-ca to be performed for this frame
	NO_CSMA_NO_IFS	Immediate Tx and SIFS(Short InterFrameSpacing) between subsequent frames
	NO_CSMA_WITH_IFS	Immediate Tx and LIFS (Long InterFrameSpacing) between subsequent frames
	CSMA_UNSLOTTED	Hardware CSMA will be performed before packet transmission with number of retries configured
	CSMA_SLOTTED	Hardware CSMA will be performed
		Beacon Enabled network - Currently not supported by PHY
performFrameRetry	Indicates whether to retries are to be performed for this frame
	true	SW retry will be performed for macMaxFrameRetries value
	false	SW retry is disabled

Returns

PHY_SUCCESS - If PHY has accepted the data from the MAC for frame transmission PHY_BUSY - If PHY is busy servicing the previous MAC request

Example

uint8_t txBuffer[LARGE_BUFFER_SIZE];
uint8_t txData[] = "Wireless!!!";
PHY_CSMAMode_t csmaMode = CSMA_UNSLOTTED;
bool performRetry = true;
PHY_FrameInfo_t txFrame;

txFrame.mpdu = txBuffer;
txBuffer[0] = sizeof(txData);
memcpy((uint8_t *)&txBuffer[1], txData, sizeof(txData));

if(PHY_SUCCESS == PHY_TxFrame(&txFrame, csmaMode, performRetry))
{
    //Frame transmission initiated successfully
}

Remarks

The return status of PHY_SUCCESS from PHY_TxFrame function indicate PHY layer accepted the request for initiation of transmission. The actual status of Transmission will be reported to higher layer through User callback function (PHY_TxDoneCallback). This function will give the status as SUCCESS, CSMA_FAILURE, RADIO_UNAVAILABLE or NO_ACK for the previous request.