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TLV320AIC3104: TLV320AIC3104EVM : can't get analog input bypass to work

Intellectual 470 points

Replies: 11

Views: 482

Part Number: TLV320AIC3104

Hi,

I have a Texas TLV320AIC3104EVM board and am trying to connect the LINE2R input to RIGHT_LOP using the analog input bypass pathway as per section 10.4 of the datasheet.

So in the 'Bypass Paths' tab I select 'LINE2R - Bypass' which generates a message in the 'Command Buffer' tab :

            w 30 6C 80

As I understand the data sheet correctly, this should result in the signal I put into MIC2R/LINE2R coming out at RIGHT_LOP.

But I get nothing out which I don't know why.

The other issue is the command sent down the I2C, hex 80 is sent to register 108 but the data sheet, page 74, says bit 7 is reserved and bit 6 should be set to enable LINE2R bypass.

Is the data sheet in error?

Any help would be appreciated.

Regards,

  • Tunstall,

    you need to make sure that the Right_LOP/M output is off.

    if that is the case, can you please provide your complete register confirguration

    best regards,
    -Steve Wilson
  • In reply to Steve-Wilson:

    Steve,

    Thanks for the response.

    I have checked the RIGHT_LOP output and it was switched off but I can't see any signal on any of the outputs unless it is severely attenuated.

    My register configuration is:

    I i2cstd

    r 30 00 10
    Read request succeeded
    Starting at 30 00: 00 00 00 10 04 00 00 80 00 00 00 01 00 00 00 80

    r 30 10 10
    Read request succeeded
    Starting at 30 10: 80 FF FF 78 78 78 78 78 78 06 00 FE 00 D0 A0 00

    r 30 20 10
    Read request succeeded
    Starting at 30 20: 00 50 00 00 01 00 00 00 00 00 00 80 80 00 00 00

    r 30 30 10
    Read request succeeded
    Starting at 30 30: 00 00 00 04 00 00 00 00 00 00 04 00 00 00 00 00

    r 30 40 10
    Read request succeeded
    Starting at 30 40: 00 04 00 00 00 00 00 00 04 00 00 00 00 00 00 00

    r 30 50 10
    Read request succeeded
    Starting at 30 50: 00 00 00 00 00 00 00 00 00 00 00 00 00 78 00 00

    r 30 60 10
    Read request succeeded
    Starting at 30 60: 00 00 00 00 00 00 02 00 00 00 00 04 80 00 00 00

    Since I posted this issue I have routed :

    'LINE2R -> RIGHT PGA -> RIGHT_LOP'

    and can see my input appearing on RIGHT_LOP. But I can't see why the bypass 'LINE2R->RIGHT_LOP' doesn't work.

    Regards

  • In reply to Tunstall_User:

    Tunstall,

    register 0x6C is not showing any configuration for your passive analog bypass.

    can you double check that it is getting written?

    best regards,
    -Steve Wilson
  • In reply to Steve-Wilson:

    Steve,

    Why do you say register 0x6c is not showing any configuration? The data I sent:

    r 30 60 10
    Read request succeeded
    Starting at 30 60: 00 00 00 00 00 00 02 00 00 00 00 04 80 00 00 00

    shows that it is set to 0x80.

    Are you saying that bit 7 of 0x80 is not a bypass bit and bit 6 should be set as per the data sheet for register 108?

    If so, that is precisely my problem. As my initial post details, if I set 'LINE2R' bypass on the 'Bypass Paths' tab, TLC320AIC3014EVM shows a message:

    w 30 6C 80

    which according to the data sheet for the TLV320AIC3104 register 108 is setting reserved bit 7 not the bypass bit which is bit 6.

    I did try setting bit 6 manually but it made no difference, no output appears on RIGHT_LOP.

    The evaluation tool software I am running is version 'V1.0.0 - 01 June 2007'.

    Regards,

  • In reply to Tunstall_User:

    Steve,
    An update, I installed the later GUI, version 1.1.1 but the same thing happens.
  • In reply to Tunstall_User:

    Tunstall,

    Yes, my mistake, my eyes lost a column there and I thought 6C was 6B. The issue is a GUI problem. when you click "line2RP bypass" it changes bit D7 but it should be changing bit D6. so rather than writing 0x80, it should write 0x40.

    If you click Line2RM bypass, this should write 0x40 to register 6C.

    I'm Interested where you found the later GUI? That was never officially released.
    best regards,
    -Steve Wilson
  • In reply to Steve-Wilson:

    Steve,

    I tried your suggestion and the 'Command Line Interface' did indeed show 0x40 been written - 'w 30 6C 40'.

    However there is still no output on RIGHT_LOP.

    As I mentioned before, I did try writing 0x40 manually in the 'Command Line Interface' and it didn't work then either so I would have been really confused if selecting 'Line2RM' worked.

    So the situation is as before, bypass doesn't seem to work but

              'LINE2R -> RIGHT PGA -> RIGHT_LOP'

    does work, with the input appearing on RIGHT_LOP.

    So why doesn't bypass work? has anyone got it to work?

    As for the GUI, version 1.1.1, I downloaded it from the EVM Texas website yesterday. I don't know the history of the one I was using, it was installed before my time on an old laptop to get round some driver issues or so I have been told.

    Regards,

  • In reply to Steve-Wilson:

    Steve,

    I tried your suggestion and the 'Command Line Interface' did indeed show 0x40 been written - 'w 30 6C 40'.

    However there is still no output on RIGHT_LOP.

    As I mentioned before, I did try writing 0x40 manually in the 'Command Line Interface' and it didn't work then either so I would have been really confused if selecting 'Line2RM' worked.

    So the situation is as before, bypass doesn't seem to work but

    'LINE2R -> RIGHT PGA -> RIGHT_LOP'

    does work, with the input appearing on RIGHT_LOP.

    So why doesn't bypass work? has anyone got it to work?

    As for the GUI, version 1.1.1, I downloaded it from the EVM Texas website yesterday. I don't know the history of the one I was using, it was installed before my time on an old laptop to get round some driver issues or so I have been told.

    Regards,
  • In reply to Tunstall_User:

    Tunstall,

    I've just hooked up an EVM and tested this as well. I realized I've only ever tested the IN1R and IN1L inputs on the TLV320AIC3104. I've tested them all on the TLV320AIC3106.

    I have the same issue as you. This looks like it may be a datasheet error. The TLV320AIC3104 is a derivative device of the TLV320AIC3106, which has two additional differential inputs (IN2RP/M and IN2LP/M) the single ended inputs are called In3R and IN3L. The Single ended inputs have no bypass path.

    I'm guessing that the single-ended inputs are what were used for the AIC3104 design, and the Differential inputs were removed. I will contact our design team, or dig into the design database to be certain and get back to you. The Design team is pretty wrapped up with new projects so it may be a few days before I hear back.

    best regards,
    -Steve Wilson
  • In reply to Steve-Wilson:

    Tunstall,

    I have confirmed with the design team. This is a datasheet error. Line2L/R on the AIC3104 and AIC3101 does not have the passivie analog bypass.

    best regards,
    -Steve Wilson

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