This daughter card implements both digital and analog audio input and output. It is based on the AD73311L chipset from Analog Devices. One mono input and one mono output are provided. This daughter card connects to the STAMP board via the Serial Port Controller Interface (SPORT0 or SPORT1) connector.

It features a 16-bit A/D conversion channel and a 16-bit D/A conversion channel. The sampling rates are programmable.

The AD73311L audio codec's internal configuration registers are configured using the processor's SPORT ports.

Some other useful documents are the datasheet and schematics.

To add support for the AD73311 to the kernel build system, a few things must be enabled properly for things to work. The structure of the driver has been changed after 2008R1.5,so things are a bit different from then on.The configuration is as following:

 Linux Kernel Configuration 
    Sound  ---> 
      [*] Sound card support
       Advanced Linux Sound Architecture  --->
        [ ] OSS Sequencer API
        [*] OSS Mixer API 
        [*] OSS PCM (digital audio) API

        Codec configuration for releases 2008R1/1.5:
        ALSA Blackfin devices  --->
           <*> AD73311L Audio support for BF53x 
           (0)   Blackfin Audio SPORT port
           (4)   PF pin for AD73311L Chip Select
       
        Codec configuration for releases after 2008R1.5:
        System on Chip audio support  --->
        <*> ALSA for SoC audio support
        <*> SoC I2S Audio for the ADI BF5xx chip 
        <*>     SoC AD73311 Audio support for Blackfin
        (4)     PF pin for AD73311L Chip Select (NEW) 

You can also set audio driver to module mode as its default, then the file uClinux-dist/vendors/AnalogDevices/BF533-STAMP/modprobe.conf or uClinux-dist/vendors/AnalogDevices/BF537-STAMP/modprobe.conf need to be modified. Just replace all ad1836 with ad73311.

Set J2 to choose a PF pin as chip select for AD73311. Because the SPORT connector on BF533 stamp board and BF537 stamp board have different PF pin defined, the jumper setting is different for them. The jumper setting should correspond to the PF pin setting in kernel configuration.

Other PF pins are not supported