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CM 108AH Highly Integrated USB Audio I/O Controller www .cmedia.com.tw Copyright© C-Media Electro nics Inc. R ev . 2.1 ︱ P age 11/27 7 F unction Description 7.1 USB Interface The CM108AH i ntegrates USB tra nsceiver, PLL…
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 10/27
6 Ordering Information
Model No.
Package
Operating Ambient
Temperature
Supply Range
CM108AH
48-pin LQFP, 7mm × 7mm × 1.4mm (plastic)
-15°C to +70°C
DVdd = 5V, AVdd = 5V
Note: Outline Dimensions are shown in inches and millimeters
48-Lead Thin Plastic Quad Flatpack (LQFP)
CM108AH Ordering Information
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 11/27
7 Function Description
7.1 USB Interface
The CM108AH integrates USB transceiver, PLL and regulator modules, meaning only a few passive components
are necessary for USB interface connection. Default USB descriptors are embedded in the CM108AH, so no
additional design effort is needed for generic USB operation. For custom orders, customers can attach a
93C46 EEPROM to override the embedded VID, PID, product and manufacturer strings, and serial number for
each set. The CM108AH automatically detects the 93C46, and the overwrite function is performed at start up.
7.1.1 Device Descriptors
Offset
Field
Size
Value (Hex)
Description
0
bLength
1
12
Total: 18 bytes
1
bDescriptorType
1
01
Device descriptor
2
bcdUSB
2
0110
USB 1.1-compliant
4
bDeviceClass
1
00
5
bDeviceSubClass
1
00
6
bDeviceProtocol
1
00
7
bMaxPacketSize0
1
40
Endpoint zero size = 64 bytes
8
idVendor
2
0d8c
Vendor ID
10
idProduct
2
0139
Product ID programmable by MSEL and MODE pin
12
bcdDevice
2
0100
Device compliant with Audio Device class
specification version 1.0
14
iManufacturer
1
01
String descriptor index describes manufacturer
15
iProduct
1
02
String descriptor index describes product
16
iSerialNumber
1
03
String descriptor index displays device serial no.
17
bNumConfigurations
1
01
Configuration number = 1
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 12/27
7.1.2 Configuration Descriptors
Offset
Field
Size
Value (Hex)
Description
0
bLength
1
09
Total: 9 bytes
1
bDescriptorType
1
02
Configuration descriptor
2
wTotalLength
2
Total length of data returned for this configuration,
programmable by MSEL and MODE pin
4
bNumInterfaces
1
04 or 03
Number of interfaces supported by this configuration,
changed by MODE pin:
EP0: control interface
EP1: ISO-OUT interface
EP2: ISO-IN interface (optional)
EP3: INT-IN (HID) interface
5
bConfigurationValue
1
01
6
iConfiguration
1
00
7
bmAttributes
1
A0 or E0
Programmable by PWRSEL
8
bMaxPower
2
32 or FA
Maximum power consumption of the USB,
programmable by MODE and PWRSEL pins