W681307DG Datasheet, PDF (148/160 Pages) Winbond – USB1.1 CODEC Microprocessor Control Unit with 32KB Mask ROM and 4KB RAM.

W681307
18.2.4
Audio Class
W681307 USB provides Audio Class interfaces so it does not need extra driver to be an USB audio device in Microsoft O/S (Windows
2000/XP). Figure 18-4 is shown an USB audio class device topology from embedded descriptors.
Audio Function
USB Streaming
ID1
MIC
IT
ID3 ID2
OT
(USB IN)
ISO IN
(EP1)
USB Streaming
(USB OUT)
ISO OUT
IT
(EP2)
ISO IN
(EP6)
ID4
ID6 ID5
OT
Interface 1 (alternate 1)
Interface 2 (alternate 1)
Figure 18-4 USB Audio Class Device Topology
W681307 USB implements Volume Control and Mute Control in Play and Record modes.
Speaker
18.2.4.1
Play Mode
We define the play mode as the traffic flows from the host to the USB device and to the baseband. The Host can turn on/off the play mode
by setting the alternative value from SET INTERFACE 2 command.
18.2.4.2
Record Mode
Define the record mode as the traffic flows from the baseband to the USB host. The Host can turn on/off the record mode by setting the
alternative value from SET INTERFACE 1 command.
18.2.4.3
Mute Control
The host can issue SET_CUR command with wValue equals to 0x100 to change the Mute function of the USB device. The host can turn
on/off the Mute as requests by the users. If the host selects Feature Unit number 1 (ID is 3), the Mute of audio stream from Mic to USB is
changed; if the host selects Feature Unit number 2 (ID is 6), the Mute of audio stream from USB to speaker is updated. The host also can
issue GET_CUR command to read back current Mute status.
Play Mode
ON
ON
OFF
OFF
Record Mode
ON
OFF
ON
OFF
Play Data to Baseband
Record Data to Host
If Play Mute is On, send 16’h0000;
otherwise same as data from host
If Play Mute is On, send 16’h0000;
otherwise same as data from host
16’h0000
16’h0000
If Record Mute is On, send 16’h0000; otherwise
same as data from Baseband
No data to host
If Record Mute is On, send 16’h0000; otherwise
same as data from Baseband
No data to host
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Publication Release Date: May, 2007
Revision 1.3