basic_rf.c

cc2430的源程序

        #endif

        rxi.ackRequest = !!(pHdr->frameControlField & BASIC_RF_FCF_ACK_BM);

        // Read the source address
        rxi.srcAddr= pHdr->srcAddr;

        // Read the packet payload
        rxi.pPayload = rxMpdu+sizeof(basicRfPktHdr_t);

        // Read the FCS to get the RSSI and CRC
        pStatusWord= rxi.pPayload+rxi.length;
        #ifdef SECURITY_CCM
        pStatusWord+= BASIC_RF_LEN_MIC;
        #endif
        rxi.rssi = pStatusWord[0];

        // Notify the application about the received data packet if the CRC is OK
        // Throw packet if the previous packet had the same sequence number
        if( (pStatusWord[1] & BASIC_RF_CRC_OK_BM) && (rxi.seqNumber != pHdr->seqNumber) ) {
            // If security is used check also that authentication passed
            #ifdef SECURITY_CCM
            if( authStatus==SUCCESS ) {
                if ( (pHdr->frameControlField & (BASIC_RF_FCF_BM)) ==
                    (BASIC_RF_FCF_NOACK | BASIC_RF_SEC_ENABLED_FCF_BM)) {
                        rxi.isReady = TRUE;
                }
            }
            #else
            if ( ((pHdr->frameControlField & (BASIC_RF_FCF_BM)) == BASIC_RF_FCF_NOACK) ) {
                rxi.isReady = TRUE;
            }
            #endif
        }

        rxi.seqNumber = pHdr->seqNumber;
    }

    // Enable RX frame done interrupt again
    halIntOff();
    halRfEnableRxInterrupt();
}


/***********************************************************************************
* GLOBAL FUNCTIONS
*/

/***********************************************************************************
* @fn          basicRfInit
*
* @brief       Initialise basic RF datastructures. Sets channel, short address and
*              PAN id in the chip and configures interrupt on packet reception
*
* @param       pRfConfig - pointer to BASIC_RF_CONFIG struct.
*                          This struct must be allocated by higher layer
*              txState - file scope variable that keeps tx state info
*              rxi - file scope variable info extracted from the last incoming
*                    frame
*
* @return      none
*/
uint8 basicRfInit(basicRfCfg_t* pRfConfig)
{
    if (halRfInit()==FAILED)
        return FAILED;

    halIntOff();

    // Set the protocol configuration
    pConfig = pRfConfig;
    rxi.pPayload   = NULL;

    txState.receiveOn = TRUE;
    txState.frameCounter = 0;

    // Set channel
    halRfSetChannel(pConfig->channel);

    // Write the short address and the PAN ID to the CC2520 RAM
    halRfSetShortAddr(pConfig->myAddr);
    halRfSetPanId(pConfig->panId);

    // if security is enabled, write key and nonce
    #ifdef SECURITY_CCM
    basicRfSecurityInit(pConfig);
    #endif

    // Set up receive interrupt (received data or acknowlegment)
    halRfRxInterruptConfig(basicRfRxFrmDoneIsr);

    halIntOn();

    return SUCCESS;
}


/***********************************************************************************
* @fn          basicRfSendPacket
*
* @brief       Send packet
*
* @param       destAddr - destination short address
*              pPayload - pointer to payload buffer. This buffer must be
*                         allocated by higher layer.
*              length - length of payload
*              txState - file scope variable that keeps tx state info
*              mpdu - file scope variable. Buffer for the frame to send
*
* @return      basicRFStatus_t - SUCCESS or FAILED
*/
uint8 basicRfSendPacket(uint16 destAddr, uint8* pPayload, uint8 length)
{
    uint8 mpduLength;
    uint8 status;

    // Turn on receiver if its not on
    if(!txState.receiveOn) {
        halRfReceiveOn();
    }

    // Check packet length
    length = min(length, BASIC_RF_MAX_PAYLOAD_SIZE);

    // Wait until the transceiver is idle
    halRfWaitTransceiverReady();

    // Turn off RX frame done interrupt to avoid interference on the SPI interface
    halRfDisableRxInterrupt();

    mpduLength = basicRfBuildMpdu(destAddr, pPayload, length);

    #ifdef SECURITY_CCM
    halRfWriteTxBufSecure(txMpdu, mpduLength, length, BASIC_RF_LEN_AUTH, BASIC_RF_SECURITY_M);
    txState.frameCounter++;     // Increment frame counter field
    halRfIncNonceTx();          // Increment nonce value
    #else
    halRfWriteTxBuf((uint8*)txMpdu, mpduLength);
    #endif

    // Turn on RX frame done interrupt for ACK reception
    halRfEnableRxInterrupt();

    // Send frame with CCA. return FAILED if not successful
    if(halRfTransmit() != SUCCESS) {
        status = FAILED;
    }

    // Wait for the acknowledge to be received, if any
    if (pConfig->ackRequest) {
        txState.ackReceived = FALSE;

        // We'll enter RX automatically, so just wait until we can be sure that the ack reception should have finished
        // The timeout consists of a 12-symbol turnaround time, the ack packet duration, and a small margin
        halMcuWaitUs((12 * BASIC_RF_SYMBOL_DURATION) + (BASIC_RF_ACK_DURATION) + (2 * BASIC_RF_SYMBOL_DURATION) + 10);

        // If an acknowledgment has been received (by RxFrmDoneIsr), the ackReceived flag should be set
        status = txState.ackReceived ? SUCCESS : FAILED;

    } else {
        status = SUCCESS;
    }

    // Turn off the receiver if it should not continue to be enabled
    if (!txState.receiveOn) {
        halRfReceiveOff();
    }

    if(status == SUCCESS) {
        txState.txSeqNumber++;
    }
    return status;

}


/***********************************************************************************
* @fn          basicRfPacketIsReady
*
* @brief       Check if a new packet is ready to be read by next higher layer
*
* @param       none
*
* @return      uint8 - TRUE if a packet is ready to be read by higher layer
*/
uint8 basicRfPacketIsReady(void)
{
    return rxi.isReady;
}


/**********************************************************************************
* @fn          basicRfReceive
*
* @brief       Copies the payload of the last incoming packet into a buffer
*
* @param       pRxData - pointer to data buffer to fill. This buffer must be
*                        allocated by higher layer.
*              len - Number of bytes to read in to buffer
*              rxi - file scope variable holding the information of the last
*                    incoming packet
*
* @return      uint8 - number of bytes actually copied into buffer
*/
uint8 basicRfReceive(uint8* pRxData, uint8 len, int16* pRssi)
{
    // Accessing shared variables -> this is a critical region
    // Critical region start
    halIntOff();
    memcpy(pRxData, rxi.pPayload, min(rxi.length, len));
    if(pRssi != NULL) {
        if(rxi.rssi < 128){
            *pRssi = rxi.rssi - halRfGetRssiOffset();
        }
        else{
            *pRssi = (rxi.rssi - 256) - halRfGetRssiOffset();
        }
    }
    rxi.isReady = FALSE;
    halIntOn();

    // Critical region end

    return min(rxi.length, len);
}


/**********************************************************************************
* @fn          basicRfGetRssi
*
* @brief       Copies the payload of the last incoming packet into a buffer
*
* @param       none

* @return      int8 - RSSI value
*/
int8 basicRfGetRssi(void)
{
    if(rxi.rssi < 128){
        return rxi.rssi - halRfGetRssiOffset();
    }
    else{
        return (rxi.rssi - 256) - halRfGetRssiOffset();
    }
}

/***********************************************************************************
* @fn          basicRfReceiveOn
*
* @brief       Turns on receiver on radio
*
* @param       txState - file scope variable
*
* @return      none
*/
void basicRfReceiveOn(void)
{
    txState.receiveOn = TRUE;
    halRfReceiveOn();
}


/***********************************************************************************
* @fn          basicRfReceiveOff
*
* @brief       Turns off receiver on radio
*
* @param       txState - file scope variable
*
* @return      none
*/
void basicRfReceiveOff(void)
{
    txState.receiveOn = FALSE;
    halRfReceiveOff();
}


/***********************************************************************************
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  YOU FURTHER ACKNOWLEDGE AND AGREE THAT THE SOFTWARE AND DOCUMENTATION ARE
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