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IEEE 1394 Interface for Audio DAC Project

shadders
Expert 1065 points
Other Parts Discussed in Thread: TSB42AC3, SRC4392

Hi,

Not sure if this has been asked before, but i am building an Audio DAC, and would like to include an IEEE1394 interface within the unit.

What i am not sure about is which Texas instruments device to use. I am completely new to the IEEE 1394 standard and the structure of the system/device operation, so any help on this area gratefully received.

If someone can indicate the best Texas Instruments device to use, this will save a lot of time examining devices that may not be suitable. Thanks.

Regards,

Richard.

  • 0
    Genius 3945 points

    TI does have a couple of FireWire device controller chips, but when I inquired about using one (TSB42AC3) in a product design (for a camera, not for audio, but that's not important), I was told, quote:

    "Thank you for your interest in TSB42AC3.  This device is intended only for high volume OEMs and ODMs with CE and/or PC end applications.  TI recommends that you look for an alternative interface solution. This is a business decision. I would not recommend usage of this or any of our 1394 link layer controllers, 1394 integrated devices in your new designs, unless your company qualifies as a large OEM/AEM since TI cannot extend support for this device."

    When I asked what qualifies us as a "large OEM," I was told, "your annual production volume should be higher than 129K units."

    So consider an alternate vendor for your project. The DICE parts (from TC Applied Technologies) and the DM1500E from ArchWave are both designed for audio applications, and are likely a better fit anyway. I cannot comment on whether their "business decisions" will preclude you from using the parts.

    -a

  • 0 in reply to Andy Peters
    Expert 1065 points

    Hi Andy, Don,

     

    Thanks for the reply - i was not sure of which device to use - and i have heard that programming the device is rather an onerous task. I would have remained with texas since their IC's seem to set the standard in the Audio computing world - always work.

     

    I am awaiting a USB device as per the PCM270X series - essentially to provide the USB 2.0 speed for higher bit rate audio, but ease of implementation. It is a shame that there is no roadmap statement from Texas, as this genre of device would be very welcome in the audio community for its ease of implementation and high bit rate.

     

    If you know of the easiest USB product to provide AES encoded Audio output (L/R, CLKLR, BITCLK etc), or S/PDIF - which can be interfaced to the SRC4392 easily, i would be grateful of any guidance. Thanks.

     

    Regards,

     

    Richard.

  • 0 in reply to shadders
    Genius 3945 points

    I don't know why TI hasn't released a follow-on to the TAS1020 that supports High Speed transfers and as such more channels at higher sampling frequencies. I mean, TI basically owns the market for Full-Speed devices, and it seems like a no-brainer. As it is, anyone who wants to do a High Speed audio product needs a high-speed controller like the Cypress EZUSB-FX2 parts, and some additional logic (small FPGA) to interface the converters to the FX2's slave port as well as implement a proper clocking scheme. Needless to say this ends up being expensive.

    Having said that, there's an additional complication in that to support audio over High Speed USB, you need to use the Audio Class 2.0 spec instead of the older Audio Class 1.0 spec (device class specs are separate from the main USB spec). Audio Class 1.0 does not work with High-Speed isochronous transfers. This means that you need a host driver that supports this spec. Even though this specification was released in 2006, only in Windows 7 has Microsoft bothered to support it, and without host driver support, there is little incentive for new product development. Note well that Mac OS X has supported Audio Class 2.0 since 10.4 a few years ago!

    -a

  • 0 in reply to Andy Peters
    Prodigy 185 points

    I did a controller with EZ-FX2 and a small CPLD for SPDIF out conversion. Now I want to interface to a SRC4392 for input sample rate conversion. Doing a CPLD for this is no big deal. It will fit in a 72Macrocell one, or perhaps even in a 36Macrocell one. But the FX2 wants to load its configuration over I2C and the SRC4392 locks SDA. Unfortunately I have only one reset to both chips and yet realized the restriction of not accessing I2C for 500us after reset. A quick and dirty patch to delay the FX2 reset did not help. Is there another known silliness I might trapped in?

    Regards

    Thomas