LMX9820ASM NSC [National Semiconductor], LMX9820ASM Datasheet - Page 16

• Manufacturer Part Number: LMX9820ASM
• Description: Bluetooth Serial Port Module
• Manufacturer: NSC [National Semiconductor]

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7.0 Functional Description
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.
1.
Motorola MC145483
OKI MSM7717
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.
Audio Path
1
8-bit log PCM
13-bit linear
(A-law only)
Format
(Continued)
Table 20. Audio Path Configuration
AAI Bit Clock
480 kHz
120 kHz
16
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, the OKI
MSM7717 codec 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.
AAI Frame Clock
8 kHz
8 kHz
AAI Frame Sync
Pulse Length
13 bits
14 bits
Revision 1.0