Hacker News Reader

Comment by userbinator | Hacker News Reader

The picture on the last page makes a great illustration of how dense electronics integration has become over the years --- all of that, and more, are now possible in a single IC:

https://www.nxp.com/docs/en/data-sheet/SAF784X.pdf

There was an article here with a good graphical description of CDs a few years ago: https://news.ycombinator.com/item?id=21185897

Unfortunately that site is gone, and the archive doesn't have a copy.

View on HN

Well, it is certainly a prototype. In the early consumer CD players the whole CD decoding datapath was split into chip with the analog part (servo amplifier, which also produces an error signal that contains the read data) and digital chip with its associated DRAM that does the rest of the decoding. It is somehow surprising how empty the single layer PCB in these early CD players is. Obviously, this level of integration was required for the technology to be commercially viable. The CD somewhat coincides with the time of cost-effective VLSI ASICs, which made this possible.

On the other hand, the modern CMOS logic runs so fast and can be so densely integrated, that the 15 years old SAF784x apparently implements the “complex analog RF” part of CD player by using DSP techniques. And the process it is made in is apparently mature enough that it can accommodate various analog functions including high-powered ones so you end up with a complete CD/MP3 player on one ASIC (if you can fit what you want to do into 64kB of ARM7TDMI code and can tolerate the sound quality and EMC implications of the integrated audio output DAC)

Maybe this copy?

https://web.archive.org/web/20200322151217/https://byuu.net/...

Reply on news.ycombinator.com