/*=================================================================================================
* @fn rxFcsIsr
*
* @brief Receive ISR state for handling the FCS.
*
* @param none
*
* @return none
*=================================================================================================
*/
static void rxFcsIsr(void)
{
uint8 crcOK;
uint8 ackWithPending = 0;
/* read FCS, rxBuf is now available storage */
MAC_RADIO_READ_RX_FIFO(rxBuf, MAC_FCS_FIELD_LEN);
/*
* The FCS has actually been replaced within the radio by a proprietary version of the FCS.
* This proprietary FCS is two bytes (same length as the real FCS) and contains:
* 1) the RSSI value
* 2) the average correlation value (used for LQI)
* 3) a CRC passed bit
*/
/* save the "CRC-is-OK" status */
crcOK = PROPRIETARY_FCS_CRC_OK(rxBuf);
/*
* See if the frame should be passed up to high-level MAC. If the CRC is OK, the
* the frame is always passed up. Frames with a bad CRC are also passed up *if*
* a special variant of promiscuous mode is active.
*/
if (crcOK || (rxPromiscuousMode == MAC_PROMISCUOUS_MODE_WITH_BAD_CRC))
{
int8 rssiDbm;
uint8 corr;
#ifdef FEATURE_SYSTEM_STATS
/* Increment diagnostic CRC success counter */
macLowLevelDiags( MAC_DIAGS_RX_CRC_PASS );
#endif /* FEATURE_SYSTEM_STATS */
/*
* As power saving optimization, set state variable to indicate physical receive
* has completed and then request turning of the receiver. This means the receiver
* can be off (if other conditions permit) during execution of the callback function.
*
* The receiver will be requested to turn off once again at the end of the receive
* logic. There is no harm in doing this.
*/
macRxActive = MAC_RX_ACTIVE_DONE;
macRxOffRequest();
/* decode RSSI and correlation values */
rssiDbm = PROPRIETARY_FCS_RSSI(rxBuf) + MAC_RADIO_RSSI_OFFSET;
MAC_RADIO_RSSI_LNA_OFFSET(rssiDbm);
corr = PROPRIETARY_FCS_CORRELATION_VALUE(rxBuf);
/* record parameters that get passed up to high-level */
pRxBuf->mac.mpduLinkQuality = macRadioComputeLQI(rssiDbm, corr);
pRxBuf->mac.rssi = rssiDbm;
pRxBuf->mac.correlation = corr;
/* set the MSDU pointer to point at start of data */
pRxBuf->mhr.p = (uint8 *) (pRxBuf + 1);
pRxBuf->msdu.p += (pRxBuf->mhr.len - pRxBuf->msdu.len);
if ((pRxBuf->internal.flags & MAC_RX_FLAG_ACK_PENDING) && (*pRxBuf->msdu.p != MAC_DATA_REQ_FRAME))
{
/* For non-data request commands, cancel the pending bit in the ACK. */
MAC_RADIO_TX_ACK();
}
/* Read the source matching result back */
if( macSrcMatchIsEnabled && MAC_RADIO_SRC_MATCH_RESULT() )
{
/* This result will not overwrite the previously determined pRxBuf->internal.flags */
ackWithPending = MAC_RX_FLAG_ACK_PENDING;
}
pRxBuf->internal.flags |= ( crcOK | ackWithPending );
/* finally... execute callback function */
macRxCompleteCallback(pRxBuf);
pRxBuf = NULL; /* needed to indicate buffer is no longer allocated */
}
else
{
#ifdef FEATURE_SYSTEM_STATS
/* Increment diagnostic CRC failure counter */
macLowLevelDiags( MAC_DIAGS_RX_CRC_FAIL );
#endif /* FEATURE_SYSTEM_STATS */
/*
* The CRC is bad so no ACK was sent. Cancel any callback and clear the flag.
* (It's OK to cancel the outgoing ACK even if an ACK was not requested. It's
* slightly more efficient to do so.)
*/
MAC_RADIO_CANCEL_ACK_TX_DONE_CALLBACK();
macRxOutgoingAckFlag = 0;
/* the CRC failed so the packet must be discarded */
MEM_FREE((uint8 **)&pRxBuf);
pRxBuf = NULL; /* needed to indicate buffer is no longer allocated */
}
/* reset threshold level, reset receive state, and complete receive logic */
MAC_RADIO_SET_RX_THRESHOLD(RX_THRESHOLD_START_LEN);
pFuncRxState = &rxStartIsr;
rxDone();
}
/*=================================================================================================
* @fn rxFcsIsr
*
* @brief Receive ISR state for handling the FCS.
*
* @param none
*
* @return none
*=================================================================================================
*/
static void rxFcsIsr(void)
{
uint8 crcOK;
/* read FCS, rxBuf is now available storage */
MAC_RADIO_READ_RX_FIFO(rxBuf, MAC_FCS_FIELD_LEN);
/*
* The FCS has actually been replaced within the radio by a proprietary version of the FCS.
* This proprietary FCS is two bytes (same length as the real FCS) and contains:
* 1) the RSSI value
* 2) the average correlation value (used for LQI)
* 3) a CRC passed bit
*/
/* save the "CRC-is-OK" status */
crcOK = PROPRIETARY_FCS_CRC_OK(rxBuf);
/*
* See if the frame should be passed up to high-level MAC. If the CRC is OK, the
* the frame is always passed up. Frames with a bad CRC are also passed up *if*
* a special variant of promiscuous mode is active.
*/
if (crcOK || (rxPromiscuousMode == MAC_PROMISCUOUS_MODE_WITH_BAD_CRC))
{
int8 rssiDbm;
uint8 corr;
/*
* As power saving optimization, set state variable to indicate physical receive
* has completed and then request turning of the receiver. This means the receiver
* can be off (if other conditions permit) during execution of the callback function.
*
* The receiver will be requested to turn off once again at the end of the receive
* logic. There is no harm in doing this.
*/
macRxActive = MAC_RX_ACTIVE_DONE;
macRxOffRequest();
/* decode RSSI and correlation values */
rssiDbm = PROPRIETARY_FCS_RSSI(rxBuf) + MAC_RADIO_RSSI_OFFSET;
corr = PROPRIETARY_FCS_CORRELATION_VALUE(rxBuf);
/* record parameters that get passed up to high-level */
pRxBuf->internal.flags |= crcOK;
pRxBuf->mac.mpduLinkQuality = macRadioComputeLQI(rssiDbm, corr);
pRxBuf->mac.rssi = rssiDbm;
pRxBuf->mac.correlation = corr;
/* set the MSDU pointer to point at start of data */
pRxBuf->msdu.p = (uint8 *) (pRxBuf + 1);
/* finally... execute callback function */
macRxCompleteCallback(pRxBuf);
pRxBuf = NULL; /* needed to indicate buffer is no longer allocated */
}
else
{
/*
* The CRC is bad so no ACK was sent. Cancel any callback and clear the flag.
* (It's OK to cancel the outgoing ACK even if an ACK was not requested. It's
* slightly more efficient to do so.)
*/
MAC_RADIO_CANCEL_ACK_TX_DONE_CALLBACK();
macRxOutgoingAckFlag = 0;
/* the CRC failed so the packet must be discarded */
MEM_FREE((uint8 *) pRxBuf);
pRxBuf = NULL; /* needed to indicate buffer is no longer allocated */
}
/* reset threshold level, reset receive state, and complete receive logic */
MAC_RADIO_SET_RX_THRESHOLD(RX_THRESHOLD_START_LEN);
pFuncRxState = &rxStartIsr;
rxDone();
}
