/***********************************************************************************
* @fn halRfReceiveOn
*
* @brief Turn receiver on
*
* @param none
*
* @return none
*/
void halRfReceiveOn(void) {
/* Flush RX FIFO if needed.
* See bug #1 in http://www.ti.com/lit/er/swrz024/swrz024.pdf */
halRfDisableRxInterrupt();
CC2520_INS_STROBE(CC2520_INS_SFLUSHRX);
uint8_t rx_fifo_cnt = CC2520_REGRD8(CC2520_RXFIFOCNT);
CC2520_INS_STROBE(CC2520_INS_SRXON);
if (rx_fifo_cnt != CC2520_REGRD8(CC2520_RXFIFOCNT)) {
CC2520_INS_STROBE(CC2520_INS_SFLUSHRX);
}
halRfEnableRxInterrupt();
}
/***********************************************************************************
* @fn halRfReadRxBufSecure
*
* @brief Decrypts and reverse authenticates with CCM then reads out received
* frame
*
* @param uint8* data - data buffer. This must be allocated by caller.
* uint8 length - number of bytes
* uint8 encrLength - number of bytes to decrypt
* uint8 authLength - number of bytes to reverse authenticate
* uuint8 m - integrity code (m=1,2,3 gives lenght of integrity
* field 4,8,16)
*
* @return HAL_RF_SUCCESS or HAL_RF_FAILED
*/
uint8 halRfReadRxBufSecure(uint8* data, uint8 length, uint8 encrLength, \
uint8 authLength, uint8 m)
{
uint8 dpuStat;
CC2520_RXBUFMOV(HIGH_PRIORITY, ADDR_RX, length, NULL);
WAIT_DPU_DONE_H();
// Find Framecounter value in received packet starting from 10th byte
// Copy in to nonce bytes (3-6) frame counter bytes
// Incoming frame uses nonce Rx
CC2520_MEMCP(HIGH_PRIORITY, 4, ADDR_RX+10, ADDR_NONCE_RX+3);
WAIT_DPU_DONE_H();
// Copy in short address to nonce bytes (7-8)
CC2520_MEMCP(HIGH_PRIORITY, 2, ADDR_RX+7, ADDR_NONCE_RX+7);
WAIT_DPU_DONE_H();
// Perform decryption and authentication
CC2520_UCCM(HIGH_PRIORITY,ADDR_KEY/16, encrLength, ADDR_NONCE_RX/16, ADDR_RX, ADDR_RX+authLength, authLength, m);
WAIT_DPU_DONE_H();
// Check authentication status
dpuStat = CC2520_REGRD8(CC2520_DPUSTAT);
// Read from RX work buffer into data buffer
CC2520_MEMRD(ADDR_RX, length, data);
if( (dpuStat & AUTHSTAT_H_BM) != AUTHSTAT_H_BM ) {
// Authentication failed
return HAL_RF_FAILED;
} else {
return HAL_RF_SUCCESS;
}
}
/***********************************************************************************
* @fn halRfReceiveOff
*
* @brief Turn receiver off
*
* @param none
*
* @return none
*/
void halRfReceiveOff(void) {
/* Flush RX FIFO if needed.
* See bug #1 in http://www.ti.com/lit/er/swrz024/swrz024.pdf */
halRfDisableRxInterrupt();
CC2520_INS_STROBE(CC2520_INS_SFLUSHRX);
uint8_t rx_fifo_cnt = CC2520_REGRD8(CC2520_RXFIFOCNT);
CC2520_INS_STROBE(CC2520_INS_SRFOFF);
if (rx_fifo_cnt != CC2520_REGRD8(CC2520_RXFIFOCNT)) {
CC2520_INS_STROBE(CC2520_INS_SFLUSHRX);
// Software clean-up
// Reset software for frame reception...
}
halRfEnableRxInterrupt();
}
/***********************************************************************************
* @fn halSampleED
*
* @brief Sample Energy Detect
*
* @param uint8 channel - channel between 11 and 26
* uint16 sampleTime - sample time in us
*
* @return int8 - sampled RSSI value
*/
int8 halSampleED(uint8 channel, uint16 sampleTime)
{
int8 rssi=0;
CC2520_REGWR8(CC2520_FREQCTRL, 0x0B + ( (channel-11) * 5));
CC2520_SRXON();
while (!CC2520_REGRD8(CC2520_RSSISTAT));
// Enable ED scan mode
CC2520_BSET(CC2520_MAKE_BIT_ADDR(CC2520_FRMCTRL0, 4));
// Spend sampleTime us accumulating the peak RSSI value
halMcuWaitUs(sampleTime);
rssi = CC2520_REGRD8(CC2520_RSSI);
// Exit the current channel
CC2520_SRFOFF();
// Disable ED scan mode
CC2520_BCLR(CC2520_MAKE_BIT_ADDR(CC2520_FRMCTRL0, 4));
return rssi;
}
