Bob,
I would greatly prefer that terminology. Folks who don't understand this stuff completely assume the wrong meaning. People who have no understanding get lead down the garden path, fat, dumb and happy.
I think if the system were to drop words, it would be forced to use interpolation - or something, to make the ultimate analogue stream "more correct". How's that? lol!
It isn't semantics here. It is the idea the words convey and I think that is very important. We should be clear.
I would greatly prefer that terminology. Folks who don't understand this stuff completely assume the wrong meaning. People who have no understanding get lead down the garden path, fat, dumb and happy.
I think if the system were to drop words, it would be forced to use interpolation - or something, to make the ultimate analogue stream "more correct". How's that? lol!
It isn't semantics here. It is the idea the words convey and I think that is very important. We should be clear.
I believe ALL ADCs write into their own RAM buffer... the transmission outside the ADC module operates over the internal Address/Data bus.
In a high end set up, a scatter/gather algorithm will transfer the data from the ADC to the DDR (RAM) or some other memory address... in a low end set up, an an interrrupt and core/DMA firmware schema will make the transfer.
I2S transmission is done outside the ADC module proper.
It's a rather complex case in that bit transmission is what the wire sees and some devices may be wired directly to the wire. But nowadays we see transmssion where the bits are assembled to (or disassembled from ) bytes/words for internal transfers. "bit perfect" thus can be handled at the network layer with CRC calculations and retransmission requests.
For this to work, the transmission bus must be running at higher rates than the AD/DAC "bit" rate.
IMHO, Bob is discussing the raw bit processing, the lower layer for data processing. ISO Layer 1.
And when discussing bit transmission, it's hard to split Layers 1, 2 and 3 since they work cohesively to ensure the lossless transmission of data.
If Bob and I were in the same office, I'd be handling Layer 3, he'd be handling Layer 1 and we'd be sharing Layer 2.
BTW, don't forget to preorder his new book. 99 bucks, paperback, in the USA.
In a high end set up, a scatter/gather algorithm will transfer the data from the ADC to the DDR (RAM) or some other memory address... in a low end set up, an an interrrupt and core/DMA firmware schema will make the transfer.
I2S transmission is done outside the ADC module proper.
It's a rather complex case in that bit transmission is what the wire sees and some devices may be wired directly to the wire. But nowadays we see transmssion where the bits are assembled to (or disassembled from ) bytes/words for internal transfers. "bit perfect" thus can be handled at the network layer with CRC calculations and retransmission requests.
For this to work, the transmission bus must be running at higher rates than the AD/DAC "bit" rate.
IMHO, Bob is discussing the raw bit processing, the lower layer for data processing. ISO Layer 1.
And when discussing bit transmission, it's hard to split Layers 1, 2 and 3 since they work cohesively to ensure the lossless transmission of data.
If Bob and I were in the same office, I'd be handling Layer 3, he'd be handling Layer 1 and we'd be sharing Layer 2.
BTW, don't forget to preorder his new book. 99 bucks, paperback, in the USA.
Last edited:
Hi Tony,
Possibly the new ones. I learned on the original types that had no integrated control or memory of any kind. All they did was have a "conversion complete" signal so you knew the data was new and valid.
SPDIF. Layers? Nope, they just spew data that comes from the internal DSP. What it did was insured that the data that came out was valid data, not that it was correct, just valid for the format. Even data transmitted over TCPIP protocols is spewed out on streaming services. You can check and make sure the data is correct, but it will not be resent. Not like a normal file transfer type protocol with anything else, as in downloading a file from a server for example.
Yes, I had to wait for a new billing cycle on my credit card for the book. With any luck, I'll pay for it once I have it and not before.
Possibly the new ones. I learned on the original types that had no integrated control or memory of any kind. All they did was have a "conversion complete" signal so you knew the data was new and valid.
SPDIF. Layers? Nope, they just spew data that comes from the internal DSP. What it did was insured that the data that came out was valid data, not that it was correct, just valid for the format. Even data transmitted over TCPIP protocols is spewed out on streaming services. You can check and make sure the data is correct, but it will not be resent. Not like a normal file transfer type protocol with anything else, as in downloading a file from a server for example.
Yes, I had to wait for a new billing cycle on my credit card for the book. With any luck, I'll pay for it once I have it and not before.
I owe you guys on the forum an apology. Somehow, for quite some time, I have not been getting DIYaudio notifications of postings on this and probably other threads, and that I why I have posted very little. I didn't understand why I was not getting notifications, but I did not delve into it because I was extremely busy writing a new book It is now completed and is due out in print in the first week in June. The publisher, Routledge/Focal put it up on Amazon for pre-order several months ago.
The title is "Designing Audio Circuits and Systems" and started out as a sort of sequel to "Designing Audio Power Amplifiers". Early on, its working title was "Designing Audio Preamplifiers", but its coverage evolved to a much broader amount of audio subject matter. It has evolved to something like designing all audio equipment except power amplifiers, including quite a bit of pro-audio subjects and equipment.
I started writing it during the COVID lock-down. It turned out to be a long 3-year journey. I have now updated my website at cordellaudio dot com, with a full description and table of contents and links to its Amazon and Routledge pages.
Although the material is mostly analog, it does include a chapter on DACs and an introductory chapter on Microcontrollers/Microcomputers. Although the very important analog parts of a DAC are covered, the digital parts like SPDIF, I2S, and sigma-delta techniques are covered.
If you check out the table of contents on my site, you may find it interesting and useful. The book has 30 chapters and comes in at about 700 pages.
BTW, last week I attended AXPONA for the second time (I still dearly miss RMAF). The resurgence of vinyl and greatly increased use of streaming audio were really on display. Almost every room had a turntable, and demos were mostly playing vinyl or streaming. Very little use of CDs and SACDs for demos. There was also a huge number of headphones and headphone amplifiers (another chapter that I enjoyed writing, including the subject of crossfeed.
Cheers,
Bob
If you are referring to email notifications not getting through then give this a try. Jason set this up a while back:
https://widgets.diyaudio.com/slrt
You should see this: