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2.1 system upto 192K using PCM5142

Prakash HK
Prodigy 250 points
Other Parts Discussed in Thread: PCM5142, PCM5142EVM-U

Dear Justin,

We want to achieve a 2.1 system working up to 192Khz sampling rate.

We are planning to use the arrangement of PCM5142 DAC as shown in the attached document

.    /cfs-file/__key/communityserver-discussions-components-files/6/8400.Options.docx

can you please confirm which of the option is more suitable.

Also

How many DSP cycles are taken by each biquad, DRC, Mux, mixer, volume control and interpolator  (we know that 512 cycles we can support 96Khz and 256 cycles supports 192Khz)

Thank you in advance.

Regards

Prakash

  • 0
    Prodigy 250 points

    Dear Justin,

    A gentle request to reply for the above post once you get time.

    Thanks in advance.
    With best regards
    Prakash

  • 0 in reply to Prakash HK
    TI__Mastermind 27990 points

    Hi Prakash,

    I believe option one would be the most optimal setup. These parts can operate with TDM, or you could have two separate I2S data lines. It sounds like you already know that you would create this setup using Biquads that you can program in the part with PurePath Studio. When using PPS you can actually create a process flow and then see how much of your processing power, or cycles, you use with the given flow. This will give you a percentage out of the miniDSP_D_Cycles in the properties window of the framework and the actual number of cycles used. However its lower limit is 352, but when in 192k sampling rate mode, you will only have 256 cycles. So go by the actual number of cycels and take it out of the number of cycles you will have available:

    384k: 128 cycles available
    192k: 256 cycles available
    96k: 512 cycles available
    etc.

    Using this resource window you can get an idea of how much each component will take in cycles with the process flow you have.

    Justin

  • 0 in reply to Justin Bohr
    Prodigy 250 points
    Dear Justin,

    Thank you very much for the reply.

    We have received a PCM5142EVM-U REV B board We are trying to connect to the EVM using Purepath studio
    via USB. I have selected PCM5120_USB_ROM.pfw

    The jumper selections is as below

    W1 Shunt pins 2-3
    W2 Shunt pins 2-3

    When I select build->run Iam getting the below error.

    -------------------
    Connecting to the EVM.
    Found board type: FWIDPCM5101EVM-S.
    Board sampling rate: 48000Hz.

    Application run failed. Error: Unable to connect to hardware
    ------------------------

    Can you please help

    Regards
    Prakash
  • 0 in reply to Justin Bohr
    Prodigy 250 points
    Dear Justin thanks for the reply

    just one quick question the resource window gives the total resource use by the flow how to find the resource used by individual components.

    Regards
    Prakash
  • 0 in reply to Justin Bohr
    Prodigy 250 points
    Dear Justin,

    Regarding 2.1 system upto 192K

    1. Can we have Stereo SDOUT
    2. In purepath there is DSP cycles available parameter it has a default 904 for PCM5142 framework, this can be changed to 1024 or higher value? what is this parameter.
    3. If we want to support 192K sampling frequency we have only 256 cycles available.
    If our process flow takes around 800 cycles and if the available cycles is 904 as set in PPS does this mean we cannot support 192K as we have only 904-800 = 96 cycles available. please clarify.
    The other option is
    if we increase the available DSP cycles from 904 to a bigger value 2048 and if our RAM flow takes around 800 cycles in this case 192K can be supported as 2048-800 = 1248 cycles available.

    Please correct me if my understanding of the above is correct.

    Regards
    Prakash
  • 0 in reply to Prakash HK
    TI__Mastermind 27990 points
    Hi Prakash,

    The cycles available is limited by clocks, not the setting in PPS. Therefore the cycles available will be what I posted above for the different sampling rates. Therefore in the resource window, you will need a process flow that does not go over 256 cycles if you want to run the process flow at 192kHz sampling rate. Changing the DSP cycles available will change the % in the resource window.

    Justin
  • 0 in reply to Justin Bohr
    Prodigy 250 points
    Thank you so much Justin

    Regards
    Prakash
  • 0 in reply to Prakash HK
    Prodigy 250 points

    Dear Justin

    Another help

    1. We created the below flow

    /cfs-file/__key/communityserver-discussions-components-files/6/8468.6215.Doc2.docx

    Can you please provide your valuable inputs

    2. The volume can be controlled by writing to the reg 61 an 62 of the DAC  then is there any specific reason we have to add volume control in the process flow.

    Regards

    Prakash

  • 0 in reply to Prakash HK
    TI__Mastermind 27990 points
    Hi Prakash,

    You are correct that this allows you two different paths of volume control. The advantages of the DSP control is that you can enable zero crossing, which will change the volume when the signal crosses 0 eliminating any audible effects of changing volume at the wrong time in a signal. Another is that SDOUT can be generated from the DSP, and can be controlled with a separate volume control in the DSP. In your process flow it is entirely reasonable to control the volume with register 61 and 62.

    Justin
  • 0 in reply to Justin Bohr
    Prodigy 250 points
    Thank you so much justin