Problems changing the codec (3204) sample rate on the ezDsp5515

Hi,

Which is the I2S master?

Regards,

Hyun

The codec.

I've found the problem and its samples being lost on the interface.  At 48000 ksps the unoptimised software loop of the example code keeps up, but at 96000 kbps it struggles.

I had added a printf every second and this also seems to have an effect on the acquisition in the next second (as if the printf merely queues a string for transfer, which takes place later).

Time to start changing the example code to use the DMA.

Hey Peter,

I am also interested in changing the example code to use DMA. Did you manage to achieve this?

Thanks

James

James,

Lets see if I can get the upload right.  The attached files consist of my work in acq.c, acq.h, error.c and error.h.  The remaining files are from the CCS directories:

• "...\ccsv4\emulation\boards\usbstk5515_v1\tests\USB_Stick_Sample\inc" (the register_xyz.h headers)
• "...\ccsv4\emulation\boards\usbstk5515_v1\include" (the usbstk5515_i2c.h header)

Use as follows:

    static Int16 samples[4096];
    ACQ_Config();
    while (1)
    {
        ACQ_Start(samples, sizeof(samples)/sizeof(samples[0]));
        ACQ_Wait();
        // Do something with the data
    }

Caveat - I extracted these files from a larger project in which they work correctly.  I cannot test them as a a separate project (I'm short of time), but I'm 95 % certain it should be OK.

Peter

Edit note added:

MikeH spotted the use of a reserved value in configuring the source address mode.  Although it works, mode 3 is reserved so it would be best to use mode 2.  i.e. In line 108 and 119 of acq.c replace 0x00C0 with 0x0080.

Hey Peter,

Thank you very much for that! I'll give it a go over the weekend and let you know how it goes. Really appreciated!

Thanks!

James

Hey Peter,

I gave it a go - however it seems to error out because my samples[] array is not in the DARAM. Sorry to sound like a noob but how can I force that array to be in DARAM?

Cheers

James

James,

I guess you're finding that my ERROR_Fatal() function is being called.

Unfortunately I don't really know how to force a variable into DARAM

I'm using the linker command file from the "...\ccsv4\emulation\boards\usbstk5515_v1\tests\aic3204" directory and when I defined the samples array as being static it ended up in DARAM.  The following line is in the file:

"   .bss      >> DARAM0|SARAM0|SARAM1  /* Global & static vars        */"

I would guess that this tells the linker to place statics in DARAM or SARAM.  If the order implies a priority it may be that your DARAM is already full.

Peter

Hey Peter,

I got it working in the end, many thanks for your help!

Cheers

James