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Discussion Groups | Analog Devices DSPs | Re: Audio CODEC recommendation

Technical discussions related to Analog Devices DSPs (including Blackfin, TigerSHARC, SHARC and ADSP-21xx DSPs).

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Audio CODEC redommendation - jaime_aranguren - Aug 18 16:37:00 2002

Hi, Could please anyone recommend an audio CODEC which allows for block processing directly though the DMA engine of a SHARC processor? I've looked at AC'97 CODECs but they use audio frames composed by TAG PHASE and other information I don't need actually. The AD1836 seemed to be interesting as didn't have TAG_PHASE and the like, uses different channels instead, but is more feasible for sample-by-sample processing, which is not what I am looking for. All of your suggestions are very welcomed. JaaC

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Re: Audio CODEC redommendation - Jaime Andres Aranguren Cardona - Aug 19 20:43:00 2002

Hi, First of all, thanks for your reply. Second, this codec still has CONTROL info in the time slot 0, STATUS in time slot 3, etc. No way to get rid of it? Third, it is a 5V part. I didn't say before, I am using ADSP-21160M, which is a 3.3V I/O part. Adding level translator doesnt' make too much sense, you understand. Fourth, in case of buying, as the AD1847 is not on the ADDS-21160M EzLite, the part is obsoleted... would get in troubles. However, I'd like to know if you've been succesful in using it with SHARCs (ADDS-21061 EzLIte, I suppose) for acquiring blocks of audio data (say 512 samples) using DMA only, then processing them while the DMA engine keeps gathering another block of samples. That will be both istructive and helpful. Please send as much info and help as you can. PS/ I've found about the AD1871, seems to be what I need, but only ADC (not full CODEC). Also interesting is the Texas Instruments' TLV320AIC23, full codec, without that annoying "side information", full compatible with TI's C54x's equivalent of serial ports. Do you have experience with any of them? Do you know how to interface it with SHARC's SPORTs??? Best regards, JaaC Nitesh Gupta wrote: Hi Jaime, I suggest AD1847. This particular is available on EZ-Kit Lite also. Nitesh jaime_aranguren wrote: Hi, Could please anyone recommend an audio CODEC which allows for block processing directly though the DMA engine of a SHARC processor? I've looked at AC'97 CODECs but they use audio frames composed by TAG PHASE and other information I don't need actually. The AD1836 seemed to be interesting as didn't have TAG_PHASE and the like, uses different channels instead, but is more feasible for sample-by-sample processing, which is not what I am looking for. All of your suggestions are very welcomed. JaaC _____________________________________ /groups.php3 --------------------------------- Jaime Andr�s Aranguren Cardona ---------------------------------

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Re: Audio CODEC recommendation - Al Clark - Aug 20 13:47:00 2002

At 03:43 PM 8/19/2002, Jaime Andres Aranguren Cardona wrote: Jaime: Any AC'97 Codec can be interfaced to a SPORT. The catch is that you have to use the shifter to take care of 20 bit slots. If you use the ADI parts you can operate with their slot16 mode. This makes for an easier driver, but you need the ADI parts. The AD1881A and AD1885 have a 3.3V Digital supply. Stay away from the AD1819. You do not need voltage translation. If you use any other AC'97 parts, the digital side will also operate at 3.3V. You can write an interrupt driver that only strips off your conversions and dumps them into a large circular buffer. You can then perform block processing on the circular buffer data. Other data converters such as the AD1836 use a separate control port. Nevertheless, the overhead of processing an AC'97 is not excessive although the interrupt handler takes some time to write and debug. John Tomarakos of ADI wrote a good ap note on this subject. Its at the ADI web site, We licence a generic AC'97 driver for the 218x or 219x for a one time charge of $500. I wrote a Sharc version as well but it is not really as polished. Our drivers read status, write commands. support variable sampling, etc. They work with all AC'97 codecs which allows you to select the best variation for your application or pay less for parts. We generally use Wolfson WM9707 AC'97 codecs. Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com > Nitesh Gupta wrote: >Hi Jaime, >I suggest AD1847. This particular is available on EZ-Kit Lite also. >Nitesh > jaime_aranguren wrote: Hi, > >Could please anyone recommend an audio CODEC which allows for block >processing directly though the DMA engine of a SHARC processor? > >I've looked at AC'97 CODECs but they use audio frames composed by TAG >PHASE and other information I don't need actually. The AD1836 seemed >to be interesting as didn't have TAG_PHASE and the like, uses >different channels instead, but is more feasible for sample-by-sample >processing, which is not what I am looking for. > >All of your suggestions are very welcomed. > >JaaC

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