FREQUENTLY ASKED QUESTIONS
1. Can I generate the clock elsewhere(external CODEC and DSP), and send a 12MHz signal to the XI pin, and tie the XO pin to ground?
2. How to test the function of Remote wake up?
3. What is the low pass filter on MIC BIAS circuit for?
4. How to setting Multi-channel on Mac?
5. Is it possible to skip "restart pc" procedure of installer on Windows?
6. Why using 997Hz to do the Full scale measurement?
7. What is the “Mode” pin with CM108AH?
8. What is the Mixer pin?
9. Why CM108AH can’t pass the new spec of USB IF?
10. Why does the Mic Record file with 1kHz Noise?
11. What the purpose of the Diode on CM6206?
12. How to use SPDIF out play Dolby / DTS content on Win7?
13. What is the meaning of "VR Volume Valid" in EEPROM content?
14. What the purpose of each output filtering component on the CM6400 schematic, like R25/R27?
15. How to detect GPIO from USB Host?
16. Does the I2C pin keep NC without EEPROM?
17. Is it possible to adjust the CM65XX/CM65XXB and let it work with AT24C128?
18. Why it takes long time to get MIC stable after plug-in my CM6500 designs to PC?
19. How to configure the address setting of EEPROM for CM65xx?
20. What is the highest VR voltage?
21. How to modify F/W from CM65XX to CM65XXB
22. How to control reset timing of CM6631A?
24. How to solve the problem of F/W Update Fail
25. Why is the Driver fail to install
26. How to avoid OS Suspending resume or Restarting, the device will become UAC1.0 or don't find the device on XP?
27. Why is there a leakage current in Power Down Mode?
28. How to improve the ENC effect?
29. Is it possible to adjust the CM65XX/CM65XXB and let it work with AT24C128?
30. Why the Cmedia chip can’t work/get the noise/no output with USB3.0 (verdor:Asmedia/Etron) chipset?
31. Can I utilize CCR 5V instead of REGV with MODE/PWRSEL pins?
32. If USB audio device is Asynchronous transfer, why audio always get the noise after system resume?
33. Why the EEPROM data is missing when plugging into the PC?
34. Why the EEPROM data is missing when plugging into the PC?
35. Can HS100B/CM119B/CM108B set to 128 words of 8 bits organization?
36. When the microphone report 24bit/96K at 1ch, why it doesn't show the 24bit on Windows mixer?
37. When PC playing the music with jack detect driver, the playback app sometimes crush while unplugging the phone jack, and it must be reopened to activate the app again. Especially occurs on playing music via Youtube.
38. Why the default initial volume are different from win7, win8.1 and win10?
39. Does CM108B I2S support stereo?
40. May I set up the default sample rating by firmware?
41. When the Youtube/online music play video/music and remove the USB device, the browser will crush. It must reopen the browser and work normally.
42. Does CM6535 support Crystal less mode?
Q1:  Can I generate the clock elsewhere(external CODEC and DSP), and send a 12MHz signal to the XI pin, and tie the XO pin to ground?
A: Yes, you can and keep the XO to N.C (floating)
Q2:  How to test the function of Remote wake up?
A:

When PC goes to standby mode or suspends modes (S3/S4) and you can resume the PC by HID buttons. (This function also needs VGA supported.)

First you need to setup your PC as below,

a. Enter the Device manager

b. Human Interface DevicesHID-compliant consumer control device

c. Select this option.

d. Let the pc enter the standby mode or suspends modes (S3/S4)

e. Resume the PC by HID buttons

Q3:  What is the low pass filter on MIC BIAS circuit for?
A:

This is used to isolate the noise from BIAS.

Q4:  How to setting Multi-channel on Mac?
A: The setting path : Go \ Utilities \ Audio MIDI Setup \ (Select device) \ Output tab \ Format \ 8ch - 16bit Integer \ Configure Speakers…
Q5:  Is it possible to skip "restart pc" procedure of installer on Windows?
A: No. The DSP effect will not workable in Windows 7/8. Sueggest to retain this step.
Q6:  Why using 997Hz to do the Full scale measurement?
A:

This frequency is selected in relation to the standard sampling frequencies

of 44.1 kHz and 48 kHz so that sampling in successive cycles occurs at

different phases of the sine. In contrast, a 1 kHz sine wave sampled at 48 kHz

will be sampled at the same 48 phases of the sine wave in each cycle.

Q7:  What is the “Mode” pin with CM108AH?
A:

This is operation mode select.

High: Speaker mode (Playback only), see the picture 1

LowHeadset mode (Playback and recording), see the picture 2

Q8:  What is the Mixer pin?
A:

This is A-A path function or Monitor function.

H: With Mixer, A-A path enable (see the picture 3)

L: Without Mixer, A-A path disable (see the picture 4)

Q9:  Why CM108AH can’t pass the new spec of USB IF?
A:

Power Current Test Result: Fail

This is a new item of USB IF.

The CM108AH/CM119A/HS100 has passed the USB IF and got the Logo certificated several years ago, but fail with new USB IF spec. If customer agrees to waiver with new USB IF spec, ALLION will sent the form to us/customer to fill them.

Q10:  Why does the Mic Record file with 1kHz Noise?
A: Because USB Power have the 1kHz Noise, it needs the RC Filter (10ohm and 10uF) on DVDD and AVDD Power to reduce this effect, DGND and AGND are separated for IC.
Q11:  What the purpose of the Diode on CM6206?
A:

It prevents from the cross talk of Microphone,because there is only one Vbias with CM6206, it should add them.

Q12:  How to use SPDIF out play Dolby / DTS content on Win7?
A: SPDIF out set passthrough mode
Q13:  What is the meaning of "VR Volume Valid" in EEPROM content?
A: If activate “VR Volume Valid”, the output volume gain will change to a fixed value(not adjustable by external VR)
Q14:  What the purpose of each output filtering component on the CM6400 schematic, like R25/R27?
A:

To reduce the pop noise. When USB power off, the C24/25 discharged to R25/27.

Q15:  How to detect GPIO from USB Host?
A:

1. Use Set report out command( 21 09 01 02 03 00 10 00) to send 16 Byte data

01 00 00 00 00 48 01 0C 00 00 00 00 00 00 00 00

01 00 00 00 00 A5 01 1D 00 00 00 00 00 00 00 00

01 00 00 00 00 FF 01 4B 00 00 00 00 00 00 00 00

 

2. Read key states from End point 7 (Byte 8) :

Bit 0: GPIO1

Bit 1: GPIO2

Bit 2: GPIO3

Bit 3: GPIO4

Bit 6: GPIO6

Bit 7: GPIO7

3. The key states can also read from get report feature command((A1 01 01 01 03 00 10 00)

Q16:  Does the I2C pin keep NC without EEPROM?
A:

No, I2C pins need to pull up to 3.3V.

Q17:  Is it possible to adjust the CM65XX/CM65XXB and let it work with AT24C128?
A:

No According to our design, the FW will check the address of EEPROM. This type of AT24C128 does not match it.

Q18:  Why it takes long time to get MIC stable after plug-in my CM6500 designs to PC?
A: Please check if you have big capacitor on XACREF pin. Usually, only one 0.1uF is necessary.
Q19:  How to configure the address setting of EEPROM for CM65xx?
A: It depends on the size of EEPROM. Refer the attachment.
Q20:  What is the highest VR voltage?
A:

1.72V is full scale

Q21:  How to modify F/W from CM65XX to CM65XXB
A:

There are 4 step shows as below:

step1. Add source code into extern.c

void exInt0Isr()

{

}

void exTimer0Isr()

{

}

void exInt1Isr()

{

}

void exTimer2Isr()

{

}

step2. Replace CM65XXB.LIB to CM65XXC.LIB

step4. Change Include paths for A51, Please direct the path to CM65xxC.LIB

Q22:  How to control reset timing of CM6631A?
A: Input a 3.3V positive pulse(duration over 5ns).
Q24:  How to solve the problem of F/W Update Fail
A: Make sure Configuration Tool is last version
Q25:  Why is the Driver fail to install
A: The driver for CM6631A must link to particular PID/VID,Please make sure the PID/VID is correct.
Q26:  How to avoid OS Suspending resume or Restarting, the device will become UAC1.0 or don't find the device on XP?
A:

Please check the Crystal Stability Over Temperature Range.

Q27:  Why is there a leakage current in Power Down Mode?
A: I2C Pins needs to pull low in Power down mode. Use GPIO to set the status to low.
Q28:  How to improve the ENC effect?
A:

The place of two microphones is really important to ENC effect, Please make sure primary microphone is very close to mouth and two microphone's place are correct.

Q29:  Is it possible to adjust the CM65XX/CM65XXB and let it work with AT24C128?
A: No. According to our design, the FW will check the address of EEPROM. This type of AT24C128 does not match it. There are two EEPROM' addresses can meet CM65XXB
When <=24C16, the address is 0xA0;
When >=24C32, the address is 0xA8;
Q30:  Why the Cmedia chip can’t work/get the noise/no output with USB3.0 (verdor:Asmedia/Etron) chipset?
A: Please update the latest driver with Asmedia/Etron USB host driver issue.
Q31:  Can I utilize CCR 5V instead of REGV with MODE/PWRSEL pins?
A: No, we suggest using REGV(3.3V). If uses 5V, it is not only affect the internal voltage but also the clock. It will create the noise.
Q32:  If USB audio device is Asynchronous transfer, why audio always get the noise after system resume?
A: OS: Only in windows 7 + SP1
Root Cause: After system resume, the system/host won’t issue feedback token, then it causes the noise after audio playback for a while.
Q33:  Why the EEPROM data is missing when plugging into the PC?
A: Check the version of IC. The old version (before K version), the I2C clock is 100K so it will find this limitation with old version. After K version, the I2C is 400K to fix this issue.
Q34:  Why the EEPROM data is missing when plugging into the PC?
A: Check the type of EEPROM. The default I2C clock of CM65XXB is 400K. There is a difference between 24LC02 and 24C02. 
24LC02, I2C clock is 100K/3.3V
24C02, I2C clock is 400K/3.3V
Q35:  Can HS100B/CM119B/CM108B set to 128 words of 8 bits organization?
A: No, they only support 64 x 16-bit organization. Please mention the configuration of EEPROM pin. 
Q36:  When the microphone report 24bit/96K at 1ch, why it doesn't show the 24bit on Windows mixer?
A: This is Microsoft driver issue/limitation. On the MAC, it shows everything on the mixer.
Q37:  When PC playing the music with jack detect driver, the playback app sometimes crush while unplugging the phone jack, and it must be reopened to activate the app again. Especially occurs on playing music via Youtube.
A: It’s Windows OS limitation.
Q38:  Why the default initial volume are different from win7, win8.1 and win10?
A: It is a define issue of the UAA (Windows inbox driver) behavior.
Q39:  Does CM108B I2S support stereo?
A: No, it only supports mono with HW design.
Q40:  May I set up the default sample rating by firmware?
A: The default sample rating is set by host.
Q41:  When the Youtube/online music play video/music and remove the USB device, the browser will crush. It must reopen the browser and work normally.
A: t is the Browser & OS limitation.
Q42:  Does CM6535 support Crystal less mode?
A: No, it must use external 12MHz Crystal
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