LMX9820ASMX/NOPB National Semiconductor, LMX9820ASMX/NOPB Datasheet - Page 16

• 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

www.national.com
7.0 Functional Description
7.4.3 Interface Select Inputs (ISEL1, ISEL2)
The interface selection pads are used for setting the UART
speed and settings. If ISEL1 and ISEL2 are unconnected,
they are pulled high by weak internal pullups, which select
a default baudrate of 921.6k baud. The settings for Stop-
bits, Startbit, and Parity are stored as internal non-volatile
storage (NVS) parameters. If a baud rate different from the
values listed in Table 18 is needed, ISEL 1 and ISEL2 must
be pulled low. This forces the device to read the UART
speed from the parameter table in NVS. The default baud
rate value programmed in NVS is 9.6k baud, however the
device firmware can be modified to support other values.
The default configuration in NVS is 1 Stopbit, 1 Startbit, and
No parity. Table 18 shows the ISEL1 and ISEL2 selection
settings.
7.4.4 Module and LInk Status Outputs
The LMX9820A provides signals that the host can use to
determine the real-time status of the radio link. The
TX_Switch_P signal (pad H3) is a real-time indication of
the current configuration (direction) of the transceiver. The
link status lines (Lstat_0 and Lstat_1, pads E8 and F8,
respectively) are GPIO lines controlled by the LMX9820A
firmware. The Host Wakeup line (Host_wu, pad F9) is
implemented using GPIO and firmware. It is used to bring
the host processor out of Sleep mode when link activity
calls for host processing. Host_wu can also be used by the
host to check if link activity is present. If Host_wu is active,
then link activity is present and the host loses network
awareness if the operating system continues to allow the
1.
2.
(Pad J13)
Motorola MC145483
OKI MSM7717
PCM slave
ISEL1
Due to internal clock divider limitations, the optimum of 512 kHz, 8 kHz cannot be reached. The values are set to the
best possible values. The clock mismatch does not result in any discernible loss in audio quality.
In PCM slave mode, parameters are stored in NVS. Bit clock and frame clock must be generated by the host interface.
1
0
1
0
Audio Path
Table 18. UART Speed Selection
2
(Pad H13)
ISEL2
1
1
0
0
1
Speed (baud)
Check NVS
Interface
921.6k
115.2k
9.6k
8-bit log PCM
(A-law only)
13-bit linear
8/16 bits
Format
(Continued)
Table 20. Audio Path Configuration
1Stop, 1Start,
From NVS
From NVS
From NVS
No Parity
Settings
UART
128 - 1024 KHz
AAI Bit Clock
480 kHz
120 kHz
16
host processor to enter Sleep mode. Table 19 presents the
definitions of the various module and link status outputs.
7.5 AUDIO PORT
Advanced Audio Interface
The Advanced Audio Interface (AAI) is an advanced ver-
sion of the Synchronous Serial Interface (SSI) that pro-
vides a full-duplex communications port to a variety of
industry-standard 13/14/15/16-bit linear or 8-bit log PCM
codecs, DSPs, and other serial audio devices.
The LMX9820A allows the support for one codec. The
firmware selects the desired audio path and interface con-
figuration by a parameter stored in NVS. The audio path
options include the Motorola MC145483 codec, OKI
MSM7717 codecs, and the PCM slave through the AAI, or
no audio.
Table 20 summarizes the audio path selection and the con-
figuration of the audio interface at the specific mode.
x
x
x
x
x
x
Table 19. Module/Link Status Definitions
1
0
x
x
x
x
AAI Frame Clock
1
0
x
x
x
x
8 kHz
8 kHz
8 kHz
x
x
x
x
0
1
At least 1 SPP link es-
tablished
No active SPP link
Transceiver = Transmit
Transceiver = Receive
Host can Sleep
Wakeup host/host
should not Sleep
AAI Frame Sync
Pulse Length
Mode
8/16 bits
13 bits
14 bits