CM109 Datasheet, PDF (14/36 Pages) C-Media Electronics – USB I/O Controller

CM109
High Integration / Low Cost USB Audio Controller
for PC Internet Phone
7.1.4 USB Audio Topology Diagram
USB Out
IT
ID = 01
Feature U nit
(volum e) (m ute)
ID = 0D
M ixer U nit
ID = 0F
Feature U nit
(volum e) (m ute)
ID = 09
enable or disable by
M S E L pin
Speaker out
OT
ID = 06
M icrophone In
IT
ID =02
Feature U nit
(volum e) (m ute)
ID = 0A
selector U nit
ID = 08
U SB IN
OT
ID = 07
USB Audio Topology Diagram
7.2 Jumper Pins and Mode Setting:
Several jumper pins can set the configuration of CM109. These jumper pin settings
affect both USB descriptors and USB audio topology. If MODE pin is pulled up to 3.3V
(speaker mode), a playback only function is activated and there is no recording function
declared to the host. At this setting, MSEL pin is ignored and only one input terminal,
one output terminal and one feature unit is declared in USB audio topology.
If MODE pin is pulled low (headset mode), a full duplex playback and recording function
is reported to the host. MSEL pin setting activates one mixer unit and one feature unit.
The following USB audio topology in Chapter: 7.1.4 is an example of headset mode.
PWRSEL pin affects the power configuration of CM109; together with MODE pin totally
4 combinations are programmable.
Date: 08/Sep/2005
- 13 -
Version: 1.3a