Hi ! Found here only old discussion about PCI cards like ESI etc... Interesting to get music from modern PC via i2s without USB Audio, any suggestions ?
I tried to find out about available multichannel PCI-e-I2S bridges a few months ago. I could find the only multichannel PCI-e chip publicly available (not custom like Creative XFi etc.) is from CMedia CM8888 which AFAIK is used e.g. in https://www.pinkfaun.com/shop/bridge/69-6445-pink-faun-i2s-bridge.htm . I asked CMedia and was told that chip is End of Life, not available from the manufacturer anymore. Even if bought from some seller, it requires a firmware for which CMedia does not want to release docs.
IMO that's one of the reasons why e.g. https://www.evga.com/articles/archive/01281/evga-nu-audio/default.asp is USB-based, using PCI-e USB xHCI host chip -> UAC2 receiver -> I2S codecs (with another advantage of not having to write custom drivers for xHCI -> UAC2 🙂 )
A number of PCI-e soundcards use legacy PCI-I2S chips with PCI-e <-> PCI bridges onboard, e.g. ESI Juli@ XT etc.
An FPGA could be programmed for this task, but FPGAs with PCI-e support are quite expensive.
IMO that's one of the reasons why e.g. https://www.evga.com/articles/archive/01281/evga-nu-audio/default.asp is USB-based, using PCI-e USB xHCI host chip -> UAC2 receiver -> I2S codecs (with another advantage of not having to write custom drivers for xHCI -> UAC2 🙂 )
A number of PCI-e soundcards use legacy PCI-I2S chips with PCI-e <-> PCI bridges onboard, e.g. ESI Juli@ XT etc.
An FPGA could be programmed for this task, but FPGAs with PCI-e support are quite expensive.
I haven't been interested in sound cards for a long time and didn't even know there was a PCI-e version of Juli@ 🙂
I need only stereo, perhaps it is worth considering of trying to get i2s from a similar board? 325Euro for finished PCI-e bridge device looks a little bit expencive for experiments
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As far as i know, my Xonar D2X, which is a PCI-E card, uses the PEX8112 bridge-chip, to run the CM6631/ Asus AV200 PCI chip.
I managed to get some chips from an old card, but i have no idea if they survived the procedure ... .
All the good Xonars (D2X, ST, STX I & II) are used not really expensive. Maybe these could be a source for chips?
I managed to get some chips from an old card, but i have no idea if they survived the procedure ... .
All the good Xonars (D2X, ST, STX I & II) are used not really expensive. Maybe these could be a source for chips?
But what do you propose to do with these bridge chips ? To get the PCI bus from PCI-E out of the PC ?
Those chips are PCI/I2S interfaces, similar to e.g. Envy24/ICE1724. E.g. CM8888DHT are still available. But the chips require a firmware to customize, there is no register-level documentation available, and C-Media will not provide it because the chips are EOL (I asked them specifically). Author of the linux alsa driver https://github.com/torvalds/linux/blob/master/sound/pci/oxygen/oxygen.c likely had some access to the docs, but likely under NDA (you could ask him).
ICE1724 chips would be more interesting as they have full docs available, but unobtainium anymore.
ICE1724 chips would be more interesting as they have full docs available, but unobtainium anymore.