Paring中的STK（short-term key） 与 bonding中的LTK（long-term key）的疑问

在TI官方的一个培训胶片上看到以下内容：

Pairing can be initiated by either the central or peripheral device
•During pairing, the two devices generate and exchange short-term keys (STK) which can be used to decrypt data packets
•In addition, either device can request to enable “bonding” to create a long-term relationship between the two devices
–A long-term key (LTK) is generated, exchanged, and stored allowing device to re-encrypt the link quickly upon re-connection, without going through the complete pairing process once again
–Profile / Service configuration data is remembered, so that the user does not need to re-configure the device every time they re-connect

但是我在1.3.2版本的代码中始终找不到关于STK和LTK配置的代码或说明，是不是1.3.2版本默认只支持LTK，即一次配对默认就绑定了？

还有一个问题，如果配置为STK，配对完成后，如果断开连接后再次连接还会要求配对，但是如果是LTK的话就不需要再次配对了？