TABLE 7. UART Frequency Settings
OP3
OP4
OP5
Function
1
0
0
UART speed read from NVS
1
0
1
UART speed 9.6 kbps
1
1
0
UART speed 115.2 kbps
1
1
1
UART speed 921.6 kbps
Note 23:
If OP3 is 1, must use 1K pull up
Note 24:
If OP4 is 1, must use 1K pull up
Note 25:
If OP5 is 1, must use 1K pull up
11.3 AUDIO PORT
11.3.1 Advanced Audio Interface
The Advanced Audio Interface (AAI) is an advanced version
of the Synchronous Serial Interface (SSI) that provides 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 interface allows the support one codec or interface. The
firmware selects the desired audio path and interface config-
uration by a parameter that is located in RAM (imported from
non-volatile storage or programmed during boot-up). The au-
dio path options include the OKI MSM7717 codec, the Win-
bond W681360/W681310 codecs and the PCM slave through
the AAI.
In case an external codec or DSP is used the LMX9838 audio
interface generates the necessary bit and frame clock driving
the interface.
Table 8 summarizes the audio path selection and the config-
uration of the audio interface at the specific modes.
The LMX9838 supports one SCO link.
TABLE 8. Audio Path Configuration
Audio setting
Interface
Format
AAI Bit Clock
AAI Frame Clock
AAI Frame Sync
Pulse Length
OKI
MSM7717
Advanced audio interface
8-bit log PCM
(a-law only)
520 kHz
8 kHz
14 Bits
Winbond
W681310
Advanced audio interface
8-bit log PCM
A-law and u-law
520 kHz
8 kHz
14 Bits
Winbond
W681360
Advanced audio interface
13-bit linear
520 kHz
8 kHz
13 Bits
PCM slave
Advanced audio interface
8/16 bits
128 - 1024 kHz
8 kHz
8/16 Bits
Note 26:
In PCM slave mode, parameters are stored in NVS. Bit clock and frame clock must be generated by the host interface.
PCM slave configuration example:
PCM slave uses the slot
0, 1 slot per frame, 16 bit linear mode, long frame sync, normal
frame sync. In this case, 0x03E0 should be stored in NVS.
See “LMX9838 Software Users Guide” for more details.
11.4 AUXILIARY PORTS
11.4.1 RESET#
The RESET# is active low and will put radio and baseband
into reset.
11.4.2 General Purpose I/Os
The LMX9838 offers 3 pins which either can be used as indi-
cation and configuration pins or can be used for General
Purpose functionality. The selection is made out of settings
derived out of the power up sequence.
In General Purpose configuration the pins are controlled hard-
ware specific commands giving the ability to set the direction,
set them to high or low or enable a weak pull-up.
In alternate function the pins have pre-defined indication func-
tionality. Please see Table 9 for a description on the alternate
indication functionality.
TABLE 9. Alternate GPIO Pin Configuration
Pin
Description
OP4/PG4
Operation Mode pin to configure
Transport Layer settings during boot-up
PG6
GPIO - Link Status indication
PG7
RF Traffic indication
11
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LMX9838
