connecting 8052 to adc and dac

You need to check some basic maths first. The PCM1802 I believe operates at

96KHz sample frequency and 24 bits. Assuming you can use a serial input and take three lots of 8 bits for each 24bit sample then you need to receive three samples every 1/96KHz secs or 8 bits every 3.5 microseconds. That's pretty damn fast for an 8051 but within the speed of the DS89C420 assuming the serial ports can go this fast.

On this basis I would say bit bashing via raw i/o ports is definitely out and your best bet would be the serial ports.

Ian

"Ian Bell" wrote

at

Off the cuff, this sampling rate and resolution sounds like one hell of an overkill for audio. Audio CD's are sampled at 16 bits, I think, and not nearly at such a fast frequency. Also, processing and re-outputting the audio through a ADC at 96K doesn't sound realistic, although it might be with a super-fast 8052. What are the norms for audio recording and processing, in regards to resolution and sampling freq? -- Mike

"Mike Turco" schreef in bericht news:OzKFb.12539$7D3.12496@fed1read02...

operates

Audio CD's are 16 bits at 44.1KHz, but 24 bit @ 96KHz doesn't sound unreasonable to me, for professional gear used in studios.

SACD, super audio CD for the home user, is 1 bit at 2.8224MHz, yes MHz. That's even more information pumped through. I have no idea what mastering equipment for SACD uses.

Anyway, I don't know what a fast 8052 can do here. Even if it is capable reading/updating the ADC/DAC, what can be done with the audio bits, in the time left...

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Thanks, Frank.
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Except that 24 bits is a s/n ratio of 144db. I wouldn't be able to make a piece of wire have a s/n ratio of 144db (:

Me neither ;)

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Thanks, Frank.
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Perhaps this is a product for people with very discerning ears ,~)

The poster did ask for suggestions.

Microchip makes a line of ADC's, and a simple DAC is just a bunch of resistors. If the OP would be more specific about what it is he is trying to accomplish, that would lead to better suggestions.

Mike

1bit @ 2.883MHz *is* 24bits @ 96KHz, that's what SACD uses.

The 8051 the OP specified has a 30nS instruction cycle - it's the fastest

8051 around.

Ian

I thought he was quite specific. He wants a single channel of audio in, apply effects to it in the digital domain and send the result to a DAC to recreate analogue audio. The 24bit/96KHz bit only came about because I took the trouble to look up the chip he said he was looking at using.

Ian

trying

took

I meant specific in terms of quality. I used to work in the toy industry and "quality" often meant "barely intelligible".

Me too and it still is.

Ian

Use an Analog Devices ADuC816 instead, it has both the ADC and DAC onboard. Or some other processor that contains both and avoid having to interface separate components.

That's why they print the word bubbles on the packaging. Many toys, I can't understand what the hell they are saying. If I see the word bubbles, that gives my audio processing firmware a list of possibles and with those in memory, I can always guess what phrase is actually being spoken.

first of all thank you for your replies. as ian pointed out i just wanted to build a sort of multi-effect processor for mono audio signals. the adc and dac actually do have a 24/96 resolution (even 24/192 fot the adc) but they also support 24/48 and 24/44.1 so i wouldn't mind that. the problem simply was how to connect them (they all are serial, but they do have the data pin, the data clock pin and the l/r clock pin (since they all are stereo)). i took a look at analog device's microconverters but their DACs only works at 12bits. otherwise they would have been perfect. maybe there are other solutions around but i didn't find them. if someone knows them...

thank you very much, CAFxX.

"Ian Bell" ha scritto nel messaggio news:3fe7f72a snipped-for-privacy@mk-nntp-1.news.uk.world>

trying

took

Yep, they're all stereo. (Or they have multiple pairs!)

Why don't use choose a DSP that has built-in I2S ports? In that case, you might actually be able to do something interesting.

Another option is to use a simple CPLD that takes I2S in and gives you parallel out, and parallel in to I2S out. If you're clever, you can figure out how to extract only one of the channels, and if you're even more clever, you'll realize that you can grab the 24-bit data in 8-bit chunks, so you don't need 48 bits of shift register. If you do it this way, you're also not wasting your micro's time bit-banging a couple of I/O ports.

I still think a DSP is the right way to go.