Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th December 2012, 01:13 PM   #1
percy is offline percy  United States
diyAudio Member
 
Join Date: Apr 2004
Location: MN
Default SPDIF receivers - internal architecture

I am curious - what exactly is a typical spdif receiver built around ? Is it a microcontroller ? Is it hardwired for all the logic and processing that goes on inside or is it software driven ?
Things like detecting the preamble and channel status bits and decoding the frames into the actual sample, and ofcourse the whole pll/clock recovery business.
And now receivers like WM880x incorporate a so called "buffer" to eliminate jitter down to 100hz. So on what platform are such things implemented ? Is it a highly customized hardware application (hardware building blocks like gates and flip flops tied together) or is it some sort of a processor handling everything by software ?
I know of "aftermarket" implementations using FPGA and XMOS and such but I asking about that $2-$5 chip you can buy from TI or CS or WM.
  Reply With Quote
Old 28th December 2012, 01:25 PM   #2
Sin Bin
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 84
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
I'd guess its a purely digital hardware state machine plus a PLL which is digital in the case of the WM8805 and analog in the others. So 'yes' to your question about is it flip flops and gates - doing it in software would require more power and more silicon real-estate I reckon.
  Reply With Quote
Old 28th December 2012, 03:44 PM   #3
percy is offline percy  United States
diyAudio Member
 
Join Date: Apr 2004
Location: MN
Quote:
Originally Posted by abraxalito View Post
So 'yes' to your question about is it flip flops and gates - doing it in software would require more power and more silicon real-estate I reckon.
Doing it in hardware would also be quite an effort. Imagine the number of digital logic building block hardware combinations you would need to make to accomplish even a simple task as detect the preamble, then extract the 13th thru 27th bit, and then decode it to 16 bits from BMC. How would you go about doing that ?
I understand in 1980 processing power especially in miniature form was not available but today its a different story.
  Reply With Quote
Old 28th December 2012, 03:52 PM   #4
Sin Bin
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 84
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Its a job for a state machine compiler- you could do this with a CPLD I guess and there are high level languages for programming them, like Abel. That's a hardware description language - http://140.113.144.123/Creative/abel_ref.pdf
  Reply With Quote
Old 28th December 2012, 07:22 PM   #5
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
noticed the RD30 has its own software spdif receiver, says its even handles 187.4khz. Probably easier for the designer to start anew than figure out the silly WM8804.

Times they are a changing.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PCM 1794 Architecture/Concept?? bear Digital Source 19 16th June 2011 07:01 PM
The Viola open architecture of Tom Colangelo rintek Solid State 2 1st July 2004 08:50 PM
DIR1703 vs. CS8416 SPDIF receivers machinow Digital Source 3 5th June 2003 07:38 AM


New To Site? Need Help?

All times are GMT. The time now is 01:49 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2