一.概述
二.建立ACL连接的过程
1. Create_Connection command
BD_ADDR,
Packet_Type,
Page_Scan_Repetition_Mode,
Reserved,
Clock_Offset,
Allow_Role_Switch
00000101 00000100 00001101 10000000 10011001 00100011 01001100 11100000 00000000 00011000 11001100 00000001 00000000 10010010
11000111 00000001
11000111 00000001
Opcode: 0x0405
Total Length: 00001101 = 0x0d = 13
BD_ADDR:10000000 10011001 00100011 01001100 11100000 00000000 = 0x00e04c239980
下图是inquiry过程中的一个extended inquiry result event：
从上图可以看出这个地址属于一个rk3066的设备，实际是一个平板电脑
Packet_Type：00011000
Page_Scan_Repetition_Mode：00000001 = 0x01(R1)
Clock_Offset：10010010 11000111 = 0xc792(18322) //CLKslave-CLKmaster
Allow_Role_Switch:00000001(本地设备是master,接受role switch)
2.
该event参数如下：
Status,
Num_HCI_Command_Packets,
Command_Opcode
00001111 00000100 00000000 00000010 00000101 00000100
EventCode: 00001111 = 0x0F
Total Length: 00000100 = 0x04
status = 00000000 = 0x00 表示command成功
Num_HCI_Command_Packets = 00000010 = 0x02
Command Opcode：和Create_connection command一样为 00000101 00000100 = 0x0405
3.Connection Complete event
Status,
Connection_Handle,
BD_ADDR,
Link_Type,
Encryption_Enabled
00000011 00001011 00000000 00001001 00000000 10000000
10011001 00100011 01001100 11100000 00000000 00000001 00000000
10011001 00100011 01001100 11100000 00000000 00000001 00000000
EventCode: 00000011 = 0x03
Total Length: 00001011 = 0x0b = 11
Status: 0x0000(Success)
Connection_Handle:00001001 00000000 = 9
BD_ADDR:
10011001 00100011 01001100 11100000 00000000 =
10011001 00100011 01001100 11100000 00000000 =
Link_Type:00000001 = 0x01（ACL connection (Data Channels)）
Encryption_Enabled：00000000（不加密）
三.总结
status event以及Connection Complete event两个event。在建立连接后，得到重要的Connection handle，建立起ACL连接，这个连接一旦建立起来，L2CAP signaling channel(CID
= 0x0001)就已经存在，L2CAP可以在这个Channel进行一些数据传输病建立L2CAp连接。这在下一篇介绍。