LMX9820ASMX/NOPB National Semiconductor, LMX9820ASMX/NOPB Datasheet - Page 24

• Manufacturer Part Number: LMX9820ASMX/NOPB
• Description: MODULE BLUETOOTH SERIAL PORT SMD
• Manufacturer: National Semiconductor

Specifications of LMX9820ASMX/NOPB

• Frequency: 2.4GHz
• Data Rate - Maximum: 704kbps
• Modulation Or Protocol: Bluetooth v1.1, Class 2
• Applications: PDA's, POS Terminals
• Power - Output: 1dBm
• Sensitivity: -81dBm
• Voltage - Supply: 2.85 V ~ 3.6 V
• Current - Receiving: 65mA
• Current - Transmitting: 68mA
• Data Interface: PCB, Surface Mount
• Memory Size: 256Kb Flash
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 116-LTCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LMX9820ASMX; LMX9820ASMXTR

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10.0 Integrated Firmware
The LMX9820A includes the full Bluetooth protocol stack
up to RFComm to support the following profiles:
— GAP (Generic Access Profile)
— SDAP (Service Discovery Application Profile)
— SPP (Serial Port Profile)
Figure 17 shows the Bluetooth protocol stack with com-
mand interpreter interface. The command interpreter offers
a number of different commands to support the functional-
ity given by the different profiles. Execution and interface
timing is handled by the control application.
The chip has an internal data area in Flash and the NVS
parameters can be found in the Software Users Guide.
10.1 FEATURES
10.1.1 Operation Modes
On boot-up, the application configures the module follow-
ing the parameters in the data area.
Automatic Mode
No Default Connections Stored
In Automatic mode the module is connectable and discov-
erable and automatically answers to service requests. The
command interpreter listens to commands and links can be
set up. The full command list is supported.
If connected by another device, the module sends an event
back to the host, where the RFComm port has been con-
nected, and switches to transparent mode.
Default Connections Stored
If default connections were stored on a previous session,
after the LMX9820A is reset, it will attempt to reconnect to
each device stored within the data Flash three times. The
host will be notified about the success of the link setup via
a link status event.
Command Mode
In Command mode, the LMX9820A does not check the
default connections section within the Data Flash. If con-
nected by another device, it will not switch to transparent
mode and continue to interpret data sent on the UART.
Figure 17. LMX9820A Software Implementation
Command Interpreter
Control Application
SPP
RFComm
Link Manager
Baseband
L2CAP
GAP
SDAP
SDP
24
Transparent Mode
The LMX9820A supports transparent data communication
from the UART interface to a Bluetooth link.
If activated, the module does not interpret the commands
on the UART which normally are used to configure and
control the module. In this case, the packets do not need to
be formatted as described in Table 27 on page 27. Instead,
all data are directly passed through the firmware to the
active Bluetooth link and the remote device.
Transparent mode can only be supported on a point-to-
point connection. To leave Transparent mode, the host
must send a UART_BREAK signal to the module
Force Master Mode
In Force Master mode, the LMX9820A tries to act like an
Access point for multiple connections. In this mode, it will
only accept a link if a master/slave role switch is accepted
by the connecting device. After successful link establish-
ment, the LMX9820A will be master and available for addi-
tional incoming links. On the first incoming link the
LMX9820A may switch to transparent mode, depending on
the setting for automatic or command mode. Additional
links will only be possible if the device is not in transparent
mode.
10.1.2 Default Connections
The LMX9820A supports the storage of up to 3 default con-
nections within its NVS. Those connections can either be
connected after reset or on demand using a specific com-
mand.
10.1.3 Event Filter
The LMX9820A uses events or indicators to notify the host
about successful commands or changes on the Bluetooth
interface. Depending on the application, the LMX9820A
can be configured. The following levels are defined:
• No Events—the LMX9820A is not reporting any events.
• Standard LMX9820A Events—only necessary events
• All Events—additional to the standard all changes at the
10.1.4 Default Link Policy
Each Bluetooth link can be configured to support mas-
ter/slave role switch, Hold mode, Sniff mode, and Park
mode. The default link policy defines the standard setting
for incoming and outgoing connections.
10.1.5 Audio Support
The LMX9820A offers commands to establish and release
synchronous connections (SCO) to support Headset or
Handsfree applications. The firmware supports one active
link with all available package types (HV1, HV2, HV3), for
routing audio data between the Bluetooth link and the
advanced audio interface. To provide the analog data inter-
face, an external audio codec is required. The LMX9820A
includes a list of codecs which can be used
10.1.6 Default Sniff operation
To support optimized power consumption, the LMX9820A
offers the ability to enable Sniff mode during link establish-
ment on incoming links or on default connection setup. The
default parameters for the Sniff mode are stored in NVS.
Optimized for passive cable replacement solutions.
will be reported.
physical layer will be reported.