C371347_139780418F8DFE40697A24CD62AD2CE5.pdf - 第14页

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

7.1.3 Content format for EEPROM (93C46)

Each address has 2-byte data, prefix `0x` means hex number

Address(Hex)

Description

0x00

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

0x01

VID 2-byte

0x02

PID 2-byte

0x03

Serial number 1st

byte

(bit15-bit8, first

character)

Serial number length

(bit7-bit0)

0x04

~

0x09

Serial number 12-byte

0x0A

Product string 1st

byte (bit15-bit8, first

character)

Product string length

(bit7-bit0) [0x3E->30,0x40->31Char]

0x0B

~

0x19

Product string 30-byte (default: USB Audio Device)

0x1A

Manufacturer string

1st byte

(bit15-bit8, first

character)

Manufacturer string length

(bit7-bit0) [0x3E->30,0x40->31Char]

0x1B

~

0x29

Manufacturer string 30-byte (default: C-Media Electronics Inc.)

0x2A

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

0x2B

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)

0x2C

bit[15:0] DAC Minimum Volume (0xD300, DAC-Min.=-37dB, default=-37dB)

0x2D

bit[15:0] DAC Maximum Volume (0x0000, DAC-Max.=0dB, default=0dB)

0x2E

bit[15:0] ADC Minimum Volume(0xEA00, ADC-Min.=-22dB, default=-12dB)

0x2F

bit[15:0] ADC Maximum Volume(0x1700, ADC-Max.=+23dB, default=+23dB)

0x30

bit[15:0] AA Minimum Volume (0xE900, AA-Min.=-23dB, default=-23dB)

0x31

bit[15:0] AA Maximum Volume (0x0800,AA-Max.+8dB, default=+8dB)

0x32

EE_OPTION2 Register

bit[3] Reserved, should be 0

bit[2] Reserved, should be 0

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

bit[1] Reserved, should be 0

bit[0] Reserved, should be 0

~ END

7.1.4 EEPROM SPI interface timing information

CS

SK

DI

DO(READ)

DO(PROG)

t

SV

t

PD1

t

DF

t

DF

t

CSH

t

SKL

t

SKH

t

CSS

t

PD0

t

DIH

t

DIS

STATUS VALID

Symbol

Parameter

Test Condition*

Min

Typ

Max

Units

f

SK

SK Clock Frequency

2.7V<=Vcc<=5.5V

0

-

200

KHz

t

SKH

SK High Time

2.7V<=Vcc<=5.5V

250

-

ns

t

SKL

SK Low Time

2.7V<=Vcc<=5.5V

250

-

ns

t

CS

Minimum CS Low Time

2.7V<=Vcc<=5.5V

250

-

ns

t

CSS

CS Setup Time

2.7V<=Vcc<=5.5V

50

-

ns

t

DIS

DI Setup Time

2.7V<=Vcc<=5.5V

100

-

ns

t

CSH

CS Hold Time

2.7V<=Vcc<=5.5V

0

-

ns

t

DIH

DI Hold Time

2.7V<=Vcc<=5.5V

100

-

ns

t

PD1

Output Delay to"1"

2.7V<=Vcc<=5.5V

-

250

ns

t

PD0

Output Delay to"0"

2.7V<=Vcc<=5.5V

-

250

ns

t

SV

CS to Status Valid

2.7V<=Vcc<=5.5V

-

250

ns

t

DF

CS to DO in High

Impedance

2.7V<=Vcc<=5.5V

-

100

ns

t

WP

Write Cycle Time

4.5V<=Vcc<=5.5V

0.1

3

10

ms

* based on ATMEL 93C46 EEPROM data

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

7.2 Jumper pins and mode setting:

The CM108B can be configured via several jumper pins. These jumper pin settings affect both USB descriptors and

USB audio topology.

7.2.1 Mode pin and msel pin

If the MODE pin is pushed up to 3.3V (speaker mode), a playback-only function is activated and no recording function

is declared to the host. At this setting, the MSEL pin is ignored and only one input terminal, one output terminal and

one feature unit is declared in the USB audio topology.

If the MODE pin is pulled low (headset mode), a full-duplex playback and recording function is reported to the host.

The MSEL pin setting activates one mixer unit and one feature unit.

 When MSEL = 1, the mixer is enabled (AA-path enabled), but with default mute setting

 When MSEL = 0, the mixer is disabled (AA-path disabled)

The above USB audio topology (7.1.4) is an example of headset mode with enabled mixer.

7.2.2 Mode pin and pwrsel pin

The PWRSEL pin affects the power configuration of the CM108B. Together with the MODE pin, there are a total of 4

programmable combinations.

Combinations

MODE

3.3V

GND

PWRSEL

3.3V

Speaker mode:

Playback only

(100mA self-powered)

Headset mode:

Playback and recording

(100mA Bus-powered)

GND

Speaker mode:

Playback only

(500mA Bus-powered)

Headset mode:

Playback and recording

(500mA Bus-powered)

USB Audio Topology Diagram