The feedback endponit doesn't work with Evaluation-Driver-for-Windows_5_72 ?

[Henry]

Update:
In the xmos_usb_audio software, the USB input stream packets size is already related to SOF speed.
I said that "USB_CHAN_IN data size is not associated with the actual host rate" is incorrect, sorry!

Testing at 48KHz, 24bit, 2ch, by the Wirkshark tool, I can see that the USB input stream packet size dynamically adjusts between 6 and 5.
And the size of the USB output stream is also dynamically adjusted between 6 and 5. It seems that implicit feedback is works.

However the random "blanks space" on the DAC line still present.

[lmariotti]

Hi Ross,

as suggested I've checked for zero-count on mclk as

Code: Select all

/* Get MCLK count */
asm volatile(" getts %0, res[%1]" : "=r" (u_tmp) : "r" (p_off_mclk));
if(u_tmp == 0)
	count_zero_clk++;

in fact count_zero_clk is > 0 after a few time of streaming, would this suggest some kind of hardware issue on MCLK side?

[Ross]

yes, that is a bad sign. Port isn't getting a mclk signal or the clock hasn't been started.

I just noticed you have a slightly odd hardware arrangement, I think its worth checking that the clockblock is indeed started, otherwise the port counter will remain at zero

You will want to make sure that start_clock(clk_name); is called.