8
ROK 101 007
LM
LM
LC
RF
LC
RF
LMP
Physical layer
Table 1: Link Control Packets Table, ACL Packets Table,
SCO packets.
Figure 8. Link manager.
used. Packets are sent over the air in timeslots with a
nominal length of 625 µs. A packet can be extended
to a maximum of 5 timeslots (DM5 and DH5 packets)
and is then sent by using the same RF channel for the
entire packet. Two types of connections are provided,
Asynchronous Connectionless Link (ACL) for data and
the Synchronous Connection Oriented Link (SCO) for
voice. Three 64 kb/s voice channels can be supported
simultaneously. Furthermore, there are also packets used
for link control purposes. A variety of different packet
types with error correction schemes and data rates
can be used over the air interface, see table 1. Also
asymmetric communication is available for high-speed
communication in one direction. The Baseband provides
the link setup and control routines for the layers
above. Furthermore, the Baseband also provides
Bluetooth security like encryption, authentication and key
management. Please refer to the Specication of the
Bluetooth System v1.1 part B for in-depth information
regarding the Baseband.
Firmware (FW)
The module includes rmware for the host controller
interface, HCI, and the link manager, LM. The FW resides
in the Flash and is available in object code format. The
module supports Device Firmware Upgrade (DFU) over
UART or USB. An Application Note, 3/1522-ROK 101 007
Uen, describing the ash procedure is available.
User Payload Symmetric Asymmetric
Type (bytes) FEC CRC Max. rate Max.rate
ID na na na na na
NULL na na na na na
POLL na na na na na
FHS 18 2/3 yes na na
Link control packets
Asymmetric
Payload User Symmetric Max rate (kb/s)
Header Payload Max. rate
Type (bytes) (bytes) FEC CRC (kb/s) Forward Reverse
DM1 1 0-17 2/3 yes 108.8 108.8 108.8
DH1 1 0-27 no yes 172.8 172.8 172.8
DM3 2 0-121 2/3 yes 258.1 387.2 54.4
DH3 2 0-183 no yes 390.4 585.6 86.4
DM5 2 0-224 2/3 yes 286.7 477.8 36.3
DH5 2 0-339 no yes 433.9 723.2 57.6
Aux1 1 0-29 no no 185.6 185.6 185.6
ACL packets
Symmetric
Payload header User Payload Max. rate
Type (bytes) (bytes) FEC CRC (kb/s)
HV1 na 10 1/3 no 64.0
HV2 na 20 2/3 no 64.0
HV3 na 30 no no 64.0
DV 1D 10+(0-9) D 2/3 D Yes D 64.0+57.6 D
SCO
Link Manager (LM)
The Link Manager in each Bluetooth module can
communicate with another Link Manager by using the
Link Manager Protocol (LMP) which is a peer to peer
protocol, see gure 8. The LMP messages have the
highest priority and are used for link-setup, security,
control and power saving modes. The receiving Link
Manager lters out the message and does not need to
acknowledge the message to the transmitting LM due
to the reliable link provided by the Baseband and the
radio. LM to LM communication can take place without
actions taken by the host. Discovery of features at other
Bluetooth enabled devices nearby can be found and
saved for later use by the host. Please refer to the
Specication of the Bluetooth System v1.1 part C for
in-depth information regarding the LMP.
Host Control Interface (HCI)
The HCI provides a uniform command I/F to the
Baseband and Link Manager and also to HW status
registers. The HCI I/F is accessed through UART or USB.
There are three different types of HCI packets:
• HCI command packets – from host to Bluetooth
module HCI.
• HCI event packets – from Bluetooth module HCI to
host.
• HCI data packets – going both ways.
It is not necessary to make use of all different commands
and events for an application. If the application is aimed
at a pre-specied prole, the capabilities of such a
prole is necessary to adjust to – see Specication of
the Bluetooth System v1.1 Proles and Application Note
5/1522-ROK 101 007 Uen.
a) With the HCI UART Transport Layer on top of HCI,
the module will communicate with a host through
the UART I/F. The PCM I/F is also available for
communicating voice.
b) With the HCI USB Transport Layer on top of the HCI,
the module will communicate with a host through the
USB. Detach and Wake_up signals are also available
for notebook implementations. Please refer to the
Specication of the Bluetooth System v1.1 part H:
1-4 for in-depth information regarding the HCI and
different transport layers.