CC2640R2F: SimpleLink SDK SimpleCentral Role example code FPGA_AUTO_CONNECT marco

Tool/software:

I found that there is a new marco called FPGA_AUTO_CONNECT in the SimpleLink SDK for CC2640R2F version 5.30.0.11 example code for simple central role which control the function call to SimpleCentral_startGapDiscovery(). And I notice that when I manually call this function, the program will stop working at function GAPCentralRole_StartDiscovery. Can anyone tell me the exact meaning of the marco FPGA_AUTO_CONNECT in this simplelink SDK? Is it required to enable the GAP discovery?

Here is related SDK example code:

#ifdef FPGA_AUTO_CONNECT
/*********************************************************************
 * @fn      SimpleCentral_startGapDiscovery
 *
 * @brief   Start discovering devices
 *
 * @param   none
 *
 * @return  none
 */
static void SimpleCentral_startGapDiscovery(void)
{
  // Start discovery
  if ((state != BLE_STATE_CONNECTED) && (!scanningStarted))
  {
    scanningStarted = TRUE;
    scanRes = 0;

    Display_print0(dispHandle, 2, 0, "Discovering...");
    Display_clearLines(dispHandle, 3, 4);

    GAPCentralRole_StartDiscovery(DEFAULT_DISCOVERY_MODE,
                                  DEFAULT_DISCOVERY_ACTIVE_SCAN,
                                  DEFAULT_DISCOVERY_WHITE_LIST);
  }
}

/*********************************************************************
 * @fn      SimpleCentral_connectToFirstDevice
 *
 * @brief   Connect to first device in list of discovered devices
 *
 * @param   none
 *
 * @return  none
 */
static void SimpleCentral_connectToFirstDevice(void)
{
  uint8_t addrType;
  uint8_t *peerAddr;

  scanIdx = 0;

  if (state == BLE_STATE_IDLE)
  {
    // connect to current device in scan result
    peerAddr = devList[scanIdx].addr;
    addrType = devList[scanIdx].addrType;

    state = BLE_STATE_CONNECTING;

    GAPCentralRole_EstablishLink(DEFAULT_LINK_HIGH_DUTY_CYCLE,
                                 DEFAULT_LINK_WHITE_LIST,
                                 addrType, peerAddr);

    Display_print0(dispHandle, 2, 0, "Connecting");
    Display_print0(dispHandle, 3, 0, Util_convertBdAddr2Str(peerAddr));
    Display_clearLine(dispHandle, 4);
  }
}
#endif // FPGA_AUTO_CONNECT

case GAP_DEVICE_INIT_DONE_EVENT:
      {
        maxPduSize = pEvent->initDone.dataPktLen;

        Display_print0(dispHandle, 1, 0, Util_convertBdAddr2Str(pEvent->initDone.devAddr));
        Display_print0(dispHandle, 2, 0, "Initialized");

        // Prompt user to begin scanning.
        Display_print0(dispHandle, 5, 0, "Discover ->");

#ifdef FPGA_AUTO_CONNECT
        SimpleCentral_startGapDiscovery();
#endif // FPGA_AUTO_CONNECT
      }
      break;