CM108B Datasheet, PDF (13/24 Pages) C-Media Electronics – A Highly Integrated USB Audio Single Chip

CM108B
USB Audio Single Chip
7.1.3 Content format for EEPROM (93C46)
Each address has 2-byte data, prefix `0x` means hex number
Address(Hex)
0x00
0x01
0x02
0x03
0x04
~
0x09
0x0A
0x0B
~
0x19
0x1A
0x1B
~
0x29
0x2A
0x2B
0x2C
0x2D
0x2E
0x2F
0x30
0x31
0x32
Description
bit[15:4] Magic Word
0x670X where X = bit 4, 3, 2, 1
bit[3] The value within address 0x2A, 0x2B, 0x32 is valid 1: valid 0: invalid
bit[2] reserved, should be 1
bit[1] serial number enable control 1: enable, 0: disable(default)
bit[0] reserved, should be 1
VID 2-byte
PID 2-byte
Serial number 1st
byte
Serial number length
(bit15-bit8, first
(bit7-bit0)
character)
Serial number 12-byte
Product string 1st
byte (bit15-bit8, first
character)
Product string length
(bit7-bit0) [0x3E->30,0x40->31Char]
Product string 30-byte (default: USB Audio Device)
Manufacturer string
1st byte
(bit15-bit8, first
character)
Manufacturer string length
(bit7-bit0) [0x3E->30,0x40->31Char]
Manufacturer string 30-byte (default: C-Media Electronics Inc.)
bit[15: 9] DAC initial volume (7-bit, default = -10dB)
bit[8: 3] ADC initial volume (6-bit, default = 8dB)
bit[2] DAC EEPROM MAX/MIN volume valid
bit[1] ADC EEPROM MAX/MIN volume valid
bit[0] AA EEPROM MAX/MIN volume valid
bit[15:11] AA initial volume (5-bit, default = -7dB)
bit[10] Reserved, should be 0
bit[9] Boost mode 0: 22dB 1:12dB (default)
bit[8] Shout down DAC analog circuits 1: shoutdown, 0: active(default)
bit[7] Total Power Control 1:enable, 0:disable(default)
bit[6] Reserved, should be 0
bit[5] MIC High Pass Filter 1:enable(default), 0:disable
bit[4] MIC PLL Adjust
1:enable, 0:disable(default)
bit[3] MIC BOOST
1:enable (default), 0:disable
bit[2] DAC Output Terminal property set to SPK or HP
1: Headset, 0: Speaker(default) bit[1] HID, 1: enable (default), 0: disable
bit[0] Remote wakeup, 1:enable, 0:disable(default)
bit[15:0] DAC Minimum Volume (0xD300, DAC-Min.=-37dB, default=-37dB)
bit[15:0] DAC Maximum Volume (0x0000, DAC-Max.=0dB, default=0dB)
bit[15:0] ADC Minimum Volume(0xEA00, ADC-Min.=-22dB, default=-12dB)
bit[15:0] ADC Maximum Volume(0x1700, ADC-Max.=+23dB, default=+23dB)
bit[15:0] AA Minimum Volume (0xE900, AA-Min.=-23dB, default=-23dB)
bit[15:0] AA Maximum Volume (0x0800,AA-Max.+8dB, default=+8dB)
EE_OPTION2 Register
bit[3] Reserved, should be 0
bit[2] Reserved, should be 0
Datasheet Revision: 1.11
Page 13 / 24
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