CM109 Datasheet, PDF (15/36 Pages) C-Media Electronics – USB I/O Controller

CM109
High Integration / Low Cost USB Audio Controller
for PC Internet Phone
Combinations
3.3V
MODE
GND
PWRSEL
Speaker Mode :
3.3V Playback Only
(Self Power with 100mA)
Headset Mode :
Playback + Recording
(Bus Power with 100mA)
Speaker Mode :
GND Playback Only
(Bus Power with 500mA)
Headset Mode :
Playback + Recording
(Bus Power with 500mA)
VSEL jumper pin sets the output voltage swing. When VSEL is connected to 5V,
output voltage swing is 3.5Vpp; when VSEL is connected to ground, output voltage
is 2.5Vpp.
7.3 HID Feature and Descriptions
HID feature is provided by CM109 so user setting to volume up, volume down, and
playback mute button pin is reported to the host to synchronize host side setting. In
addition, all CM109 internal registers can be accessed via HID function call.
USB protocols can configure devices at startup or when they are plugged in at run time.
These devices are broken into various device classes. Each device class defines the
common behavior and protocols for devices that serve similar functions. The HID
(Human Interface Device) class is one of the device classes.
The HID class consists primarily of devices that are used by humans to control the
operation of computer systems. Typical examples of HID class devices include:
- Keyboards and pointing devices, for example: mouse, trackballs, and joysticks.
- Front-panel controls, for example: knobs, switches, buttons, and sliders.
- Controls that might be found on devices such as VCR remote controls, games or
simulation devices, for example: data gloves, throttles, and steering wheels.
- Devices that may not require human interaction but provide data in a similar format
to HID class devices, for example: bar-code readers, thermometers, or voltmeters.
Date: 08/Sep/2005
- 14 -
Version: 1.3a