Search found 1119 matches

by infiniteimprobability
Thu Dec 20, 2018 10:54 am
Forum: Projects
Topic: USB Audio VU meter
Replies: 11
Views: 24241

Re: USB Audio VU meter

Here you go. Looks like it has dregs of the VU project in it but I believe it all works.
by infiniteimprobability
Tue Dec 04, 2018 11:12 am
Forum: Processors
Topic: USB 3 streaming audio from XMOS?
Replies: 2
Views: 32558

Re: USB 3 streaming audio from XMOS?

There is no schedule currently, because it requires a major change at the physical layer (MGBT support) rather than a "plain old 480Mbps PHY" which is already on chip. But it would be interesting to understand the use case for this to help build a business case. What application do you see...
by infiniteimprobability
Fri Nov 30, 2018 2:51 pm
Forum: Getting started
Topic: getting started question(s)...
Replies: 1
Views: 46100

Re: getting started question(s)...

Quick answers.. 1. Does the USB interface present itself to Linux as a typical USB device? Yes - in most flavours of Linux, UAC1 & UAC2 are supported. The Xmos USB device is class compliant. In other words can I just hook up ALSA to the stream? Yes, but please do share or check which distro/host...
by infiniteimprobability
Wed Oct 24, 2018 5:42 pm
Forum: Development Tools and Programming
Topic: Xcore 200 Issue with 3 Bytes per sub slot
Replies: 1
Views: 17518

Re: Xcore 200 Issue with 3 Bytes per sub slot

Looking at your waveform, it looks like underflow. Ie. samples are being provided too slowly and the buffer underflows (and outputs zero). This doesn't really make sense though.. Is the overall period of the sawtooth what you'd expect? If not, perhaps the host isn't keeping up!? I think this will re...
by infiniteimprobability
Wed Oct 24, 2018 3:29 pm
Forum: Development Tools and Programming
Topic: xtcp_lwip core usage
Replies: 8
Views: 41685

Re: xtcp_lwip core usage

I'm pretty sure the AR8035 PHY PCS only supports RGMII (which requires the 1G component), whereas the Xmos 100M lib_ethernet version expects MII.

I think you'll need a change of HW to use the more compact MII/100M lib - sorry!
by infiniteimprobability
Tue Oct 16, 2018 5:28 pm
Forum: Development Tools and Programming
Topic: Xcore200 USB channel limitation
Replies: 11
Views: 18030

Re: Xcore200 USB channel limitation

We can't accept 3Byte words because unpacking is not truly parallel to the other processes of the audio stream. For each channel, a sample is received from USB then unpacked then send to mixer. And then another sample for another channel and so on. So the mixing thread is waiting for every sample t...
by infiniteimprobability
Wed Oct 10, 2018 2:50 pm
Forum: Development Tools and Programming
Topic: Xcore200 USB channel limitation
Replies: 11
Views: 18030

Re: Xcore200 USB channel limitation

Sorry to read that there is not yet support of multiple frame per microframe. Has anybody worked on it, even as a prototype version ? I think there is a very early experiment on a branch but it was never completed. There's another thread with more detail about it here: http://www.xcore.com/viewtopi...
by infiniteimprobability
Mon Oct 08, 2018 3:14 pm
Forum: Development Tools and Programming
Topic: Xcore200 USB channel limitation
Replies: 11
Views: 18030

Re: Xcore200 USB channel limitation

This is a good point - we occasionally need to allow for 7 samples per SOF period in the case where f > 48000Hz. So 1024 / 7 / 4 = 36.57 channels and.. 1024 / 7 / 3 = 48.76 channels Support for multiple frames per microframe is not yet implemented for Isochronous endpoint so it looks like 3 byte slo...
by infiniteimprobability
Fri Oct 05, 2018 8:19 am
Forum: Development Tools and Programming
Topic: Xcore200 USB channel limitation
Replies: 11
Views: 18030

Re: Xcore200 USB channel limitation

Hmm that's interesting - I wonder if the host is even trying to open the stream? It would be good to see a USB trace to see if the Alt interface changed on stream start. This will tell us if the host is deciding to reject the request or if the firmware is not handling it. One thing to try is to chan...
by infiniteimprobability
Tue Oct 02, 2018 9:38 am
Forum: Applications
Topic: Min Power consumption for a UAC2 to I2S bridge?
Replies: 3
Views: 7736

Re: Min Power consumption for a UAC2 to I2S bridge?

Thanks! Is it possible to somehow profile what parts of the code vs peripherals that's drawing current? Yes - we have done that and the above recommendations are as a result of the work. The main offender is the XUD task which talks to the PHY. It has to run at full tilt in all states because it ta...