LMX9820SB/NOPB National Semiconductor, LMX9820SB/NOPB Datasheet - Page 21

• Manufacturer Part Number: LMX9820SB/NOPB
• Manufacturer: National Semiconductor

Specifications of LMX9820SB/NOPB

• Lead Free Status / Rohs Status: Compliant

Revision 1.0
10.0 Integrated Firmware
The LMX9820 includes the full Bluetooth stack up to
RFComm to support the following profiles:
• GAP (Generic Access Profile)
• SDAP (Service Discovery Application Profile)
• SPP (Serial Port Profile)
Figure 15 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 that includes
the parameters shown in Table 25 on page 22.
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,
once the LMX9820 is reset, it will attempt to connect 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 LMX9820 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 15. LMX9820 Software Implementation
SPP
Command Interpreter
RFComm
Control Application
Link Manager
Baseband
L2CAP
GAP
SDAP
SDP
21
Transparent Mode
The LMX9820 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. The packages don’t need to be format-
ted as described in Table 27 on page 24. Instead all data
are directly passed through the firmware to the active blue-
tooth 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 tries to act like an Accesspoint for
multiple connections. For this it will only accept the link if a
Master/slave role switch is accepted by the connecting
device. After successful link establishment the LMX9820
will be Master and available for additional incoming links.
On the first incoming link the LMX9820 will switch to trans-
parent 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 LMX9820 supports the storage of up to 3 devices
within its NVS. Those connections can either be connected
after reset or on demand using a specific command.
10.1.3 Event Filter
The LMX9820 uses events or indicators to notify the host
about successful commands or changes at the bluetooth
interface. Depending on the application the LMX9820 can
be configured. The following levels are defined:
• No Events:
• Standard LMX9820 events:
• All events:
10.1.4 Default Link Policy
Each Bluetooth Link can be configured to support M/S role
switch, Hold Mode, Sniff Mode and Park Mode. The default
link policy defines the standard setting for incoming and
outgoing connections.
– The LMX9820 is not reporting any events. Optimized
– only necessary events will be reported
– Additional to the standard all changes at the physical
for passive cable replacement solutions.
layer will be reported.
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