使用lightblue与cc2640配对时，弹出来要求输入密码的框，但是没有输入密码，等几秒中就自己连上了，也可以写特征值，这是为什么？

// Setup the GAP Bond Manager
{
uint8_t pairMode = GAPBOND_PAIRING_MODE_INITIATE;
uint8_t mitm = true;
uint8_t ioCap = GAPBOND_IO_CAP_DISPLAY_ONLY;
uint8_t bonding = true;

// Set pairing mode
GAPBondMgr_SetParameter(GAPBOND_PAIRING_MODE, sizeof(uint8_t), &pairMode);

// Set authentication requirements
GAPBondMgr_SetParameter(GAPBOND_MITM_PROTECTION, sizeof(uint8_t), &mitm);

// Set I/O capabilities
GAPBondMgr_SetParameter(GAPBOND_IO_CAPABILITIES, sizeof(uint8_t), &ioCap);

// Sst bonding requirements
GAPBondMgr_SetParameter(GAPBOND_BONDING_ENABLED, sizeof(uint8_t), &bonding);

// Register and start Bond Manager
VOID GAPBondMgr_Register(&multi_role_BondMgrCBs);
}