/**************************************************************************************************
* @fn macTxDoneCallback
*
* @brief -
*
* @param -
*
* @return none
**************************************************************************************************
*/
void macTxDoneCallback(uint8 status)
{
if (status == MAC_TXDONE_SUCCESS)
{
/* see if ACK was requested */
if (!txAckReq)
{
/* ACK was not requested, transmit is complete */
txComplete(MAC_SUCCESS);
}
else
{
/*
* ACK was requested - must wait to receive it. A timer is set
* to expire after the timeout duration for waiting for an ACK.
* If an ACK is received, the function macTxAckReceived() is called.
* If an ACK is not received within the timeout period,
* the function macTxAckTimeoutCallback() is called.
*/
macTxListenForAck = TRUE;
MAC_RADIO_TX_REQUEST_ACK_TIMEOUT_CALLBACK();
}
}
else if (status == MAC_TXDONE_CHANNEL_BUSY)
{
MAC_ASSERT((macTxType == MAC_TX_TYPE_SLOTTED_CSMA) || (macTxType == MAC_TX_TYPE_UNSLOTTED_CSMA));
/* clear channel assement failed, follow through with CSMA algorithm */
nb++;
if (nb > macPib.maxCsmaBackoffs)
{
txComplete(MAC_CHANNEL_ACCESS_FAILURE);
}
else
{
macTxBe = MIN(macTxBe+1, macPib.maxBe);
txCsmaPrep();
txCsmaGo();
}
}
else
{
MAC_ASSERT(status == MAC_TXDONE_INSUFFICIENT_TIME);
txComplete(MAC_NO_TIME);
}
}
/**************************************************************************************************
* @fn macTxAckReceivedCallback
*
* @brief This function is called by the receive logic when an ACK is received and
* transmit logic is listening for an ACK.
*
* @param seqn - sequence number of received ACK
* @param pendingFlag - set if pending flag of ACK is set, cleared otherwise
*
* @return none
**************************************************************************************************
*/
MAC_INTERNAL_API void macTxAckReceivedCallback(uint8 seqn, uint8 pendingFlag)
{
halIntState_t s;
/* only process if listening for an ACK; critical section prevents race condition problems */
HAL_ENTER_CRITICAL_SECTION(s);
if (macTxActive == MAC_TX_ACTIVE_LISTEN_FOR_ACK)
{
macTxActive = MAC_TX_ACTIVE_POST_ACK;
MAC_RADIO_TX_CANCEL_ACK_TIMEOUT_CALLBACK();
HAL_EXIT_CRITICAL_SECTION(s);
/* see if the sequence number of received ACK matches sequence number of packet just sent */
if (seqn == txSeqn)
{
/*
* Sequence numbers match so transmit is successful. Return appropriate
* status based on the pending flag of the received ACK.
*/
if (pendingFlag)
{
txComplete(MAC_ACK_PENDING);
}
else
{
txComplete(MAC_SUCCESS);
}
}
else
{
/* sequence number did not match; per spec, transmit failed at this point */
txComplete(MAC_NO_ACK);
}
}
else
{
HAL_EXIT_CRITICAL_SECTION(s);
}
}
/**************************************************************************************************
* @fn macTxAckTimeoutCallback
*
* @brief This function is called if ACK is not received within timeout period.
*
* @param none
*
* @return none
**************************************************************************************************
*/
void macTxAckTimeoutCallback(void)
{
halIntState_t s;
HAL_ENTER_CRITICAL_SECTION(s);
if (macTxListenForAck)
{
macTxListenForAck = FALSE;
HAL_EXIT_CRITICAL_SECTION(s);
txComplete(MAC_NO_ACK);
}
HAL_EXIT_CRITICAL_SECTION(s);
}
/**************************************************************************************************
* @fn macTxAckReceived
*
* @brief Function called by interrupt routine when an ACK is received.
*
* @param seqn - sequence number of received ACK
* @param pendingFlag - set to TRUE if pending flag of ACK is set, FALSE otherwise
*
* @return none
**************************************************************************************************
*/
void macTxAckReceived(uint8 seqn, uint8 pendingFlag)
{
halIntState_t s;
/* only process the received ACK if the macTxListenForAck flag is set */
HAL_ENTER_CRITICAL_SECTION(s);
if (macTxListenForAck)
{
macTxListenForAck = FALSE;
HAL_EXIT_CRITICAL_SECTION(s);
/* cancel the ACK callback */
MAC_RADIO_TX_CANCEL_ACK_TIMEOUT_CALLBACK();
/* see if the sequence number of received ACK matches sequence number of packet just sent */
if (seqn == txSeqn)
{
/*
* Sequence numbers match so transmit is successful. Return appropriate
* status based on the pending flag of the received ACK.
*/
if (pendingFlag)
{
txComplete(MAC_ACK_PENDING);
}
else
{
txComplete(MAC_SUCCESS);
}
}
else
{
/* sequence number did not match; per spec, transmit failed at this point */
txComplete(MAC_NO_ACK);
}
}
HAL_EXIT_CRITICAL_SECTION(s);
}
/*=================================================================================================
* @fn txCsmaGo
*
* @brief -
*
* @param none
*
* @return none
*=================================================================================================
*/
static void txCsmaGo(void)
{
if (macTxType == MAC_TX_TYPE_SLOTTED_CSMA)
{
if (macTxCsmaBackoffDelay >= macDataTxTimeAvailable())
{
txComplete(MAC_NO_TIME);
return;
}
}
MAC_RADIO_TX_GO_CSMA();
}
/**************************************************************************************************
* @fn macTxDoneCallback
*
* @brief This callback is executed when transmit completes.
*
* @param none
*
* @return none
**************************************************************************************************
*/
MAC_INTERNAL_API void macTxDoneCallback(void)
{
halIntState_t s;
/*
* There is a small chance this function could be called twice for a single transmit.
* To prevent logic from executing twice, the state variable macTxActive is used as
* a gating mechanism to guarantee single time execution.
*/
HAL_ENTER_CRITICAL_SECTION(s);
if (macTxActive == MAC_TX_ACTIVE_GO)
{
if (macRxActive)
{
/* RX was partly done just before TX. Reset the RX state. */
macTxCollisionWithRxCallback();
}
/* see if ACK was requested */
if (!txAckReq)
{
macTxActive = MAC_TX_ACTIVE_DONE;
HAL_EXIT_CRITICAL_SECTION(s);
/* ACK was not requested, transmit is complete */
txComplete(MAC_SUCCESS);
}
else
{
/*
* ACK was requested - must wait to receive it. A timer is set
* to expire after the timeout duration for waiting for an ACK.
* If an ACK is received, the function macTxAckReceived() is called.
* If an ACK is not received within the timeout period,
* the function macTxAckNotReceivedCallback() is called.
*/
macTxActive = MAC_TX_ACTIVE_LISTEN_FOR_ACK;
MAC_RADIO_TX_REQUEST_ACK_TIMEOUT_CALLBACK();
HAL_EXIT_CRITICAL_SECTION(s);
}
}
else
{
HAL_EXIT_CRITICAL_SECTION(s);
}
}
/**************************************************************************************************
* @fn macTxAckNotReceivedCallback
*
* @brief This function is called by the receive logic when transmit is listening
* for an ACK but something else is received. It is also called if the
* listen-for-ACK timeout is reached.
*
* @brief
*
* @param none
*
* @return none
**************************************************************************************************
*/
MAC_INTERNAL_API void macTxAckNotReceivedCallback(void)
{
halIntState_t s;
/* only process if listening for an ACK; critical section prevents race condition problems */
HAL_ENTER_CRITICAL_SECTION(s);
if (macTxActive == MAC_TX_ACTIVE_LISTEN_FOR_ACK)
{
macTxActive = MAC_TX_ACTIVE_POST_ACK;
MAC_RADIO_TX_CANCEL_ACK_TIMEOUT_CALLBACK();
HAL_EXIT_CRITICAL_SECTION(s);
/* a non-ACK was received when expecting an ACK, per spec transmit is over at this point */
txComplete(MAC_NO_ACK);
}
else
{
HAL_EXIT_CRITICAL_SECTION(s);
}
}
/**************************************************************************************************
* @fn macTxChannelBusyCallback
*
* @brief This callback is executed if a CSMA transmit was attempted but the channel
* was busy.
*
* @param none
*
* @return none
**************************************************************************************************
*/
MAC_INTERNAL_API void macTxChannelBusyCallback(void)
{
MAC_ASSERT((macTxType == MAC_TX_TYPE_SLOTTED_CSMA) || (macTxType == MAC_TX_TYPE_UNSLOTTED_CSMA));
/* turn off receiver if allowed */
macTxActive = MAC_TX_ACTIVE_CHANNEL_BUSY;
macRxOffRequest();
/* clear channel assement failed, follow through with CSMA algorithm */
nb++;
if (nb > pMacPib->maxCsmaBackoffs)
{
txComplete(MAC_CHANNEL_ACCESS_FAILURE);
}
else
{
macTxBe = MIN(macTxBe+1, pMacPib->maxBe);
txCsmaPrep();
macTxActive = MAC_TX_ACTIVE_GO;
txCsmaGo();
}
}
/**************************************************************************************************
* @fn macTxFrame
*
* @brief Transmit the frame pointed to by pMacDataTx with the specified type.
* NOTE! It is not legal to call this function from interrupt context.
*
* @param txType - type of transmit
*
* @return none
**************************************************************************************************
*/
MAC_INTERNAL_API void macTxFrame(uint8 txType)
{
MAC_ASSERT(!macTxActive); /* transmit on top of transmit */
/* mark transmit as active */
macTxActive = MAC_TX_ACTIVE_INITIALIZE;
/*
* The MAC will not enter sleep mode if there is an active transmit. However, if macSleep() is
* ever called from interrupt context, it possible to enter sleep state after a transmit is
* intiated but before macTxActive is set. To recover from this, the transmit must be aborted
* and proper notificiation given to high-level.
*/
if (macSleepState != MAC_SLEEP_STATE_AWAKE)
{
/* notify high-level that transmit had to be aborted */
txComplete(MAC_TX_ABORTED);
/* exit from transmit logic */
return;
}
/* save transmit type */
macTxType = txType;
/*-------------------------------------------------------------------------------
* Prepare for transmit.
*/
if (macTxType == MAC_TX_TYPE_SLOTTED)
{
MAC_RADIO_TX_PREP_SLOTTED();
}
#ifdef FEATURE_GREEN_POWER
else if (macTxType == MAC_TX_TYPE_GREEN_POWER)
{
txGreenPowerPrep();
}
#endif /* #ifdef FEATURE_GREEN_POWER */
else
{
MAC_ASSERT((macTxType == MAC_TX_TYPE_SLOTTED_CSMA) || (macTxType == MAC_TX_TYPE_UNSLOTTED_CSMA));
nb = 0;
macTxBe = (pMacDataTx->internal.txOptions & MAC_TXOPTION_ALT_BE) ? pMacPib->altBe : pMacPib->minBe;
if ((macTxType == MAC_TX_TYPE_SLOTTED_CSMA) && (pMacPib->battLifeExt))
{
macTxBe = MIN(2, macTxBe);
}
txCsmaPrep();
}
/*-------------------------------------------------------------------------------
* Load transmit FIFO unless this is a retransmit. No need to write
* the FIFO again in that case.
*/
if (!txRetransmitFlag)
{
uint8 * p;
uint8 lenMhrMsdu;
MAC_ASSERT(pMacDataTx != NULL); /* must have data to transmit */
/* save needed parameters */
txAckReq = MAC_ACK_REQUEST(pMacDataTx->msdu.p);
txSeqn = MAC_SEQ_NUMBER(pMacDataTx->msdu.p);
/* set length of frame (note: use of term msdu is a misnomer, here it's actually mhr + msdu) */
lenMhrMsdu = pMacDataTx->msdu.len;
/* calling code guarantees an unused prepended byte */
p = pMacDataTx->msdu.p - PREPENDED_BYTE_LEN;
/* first byte of buffer is length of MPDU */
*p = lenMhrMsdu + MFR_LEN;
/*
* Flush the TX FIFO. This is necessary in case the previous transmit was never
* actually sent (e.g. CSMA failed without strobing TXON). If bytes are written to
* the FIFO but not transmitted, they remain in the FIFO to be transmitted whenever
* a strobe of TXON does happen.
*/
MAC_RADIO_FLUSH_TX_FIFO();
/* write bytes to FIFO, prepended byte is included, MFR is not (it's generated by hardware) */
MAC_RADIO_WRITE_TX_FIFO(p, PREPENDED_BYTE_LEN + lenMhrMsdu);
}
/*-------------------------------------------------------------------------------
* If not receiving, start the transmit. If receive is active
* queue up the transmit.
*
* Critical sections around the state change prevents any sort of race condition
* with macTxStartQueuedFrame(). This guarantees function txGo() will only be
* called once.
*/
{
halIntState_t s;
HAL_ENTER_CRITICAL_SECTION(s);
if (!macRxActive && !macRxOutgoingAckFlag)
{
macTxActive = MAC_TX_ACTIVE_GO;
HAL_EXIT_CRITICAL_SECTION(s);
txGo();
}
else
{
macTxActive = MAC_TX_ACTIVE_QUEUED;
HAL_EXIT_CRITICAL_SECTION(s);
}
}
}
