You are correct, CRUS and LSI are not competing with each other in DVD. Since I am an investor in both, I have recently done some research on the subject.
The CRUS chip is a controller for DVD-ROM or DVD-player. Its functions include signal processing (turning the analog signal from the disc into a digital bit stream), servo control (controlling where the head moves on the platter), Content Scramble System (CSS) authentication (not sure about this, I think it means it checks to see that it's properly encrypted but doesn't actually decrypt anything), error correction (gets rid of errors in the digital bit stream, one of the more complicated functions), and a CD-ROM decoder. It then passes the MPEG-2 data to another chip for decoding.
The LSI DVD decoder chip does CSS decryption and decodes the MPEG-2 data into audio and video.
The DVD controller technology at CRUS is based on their CD-ROM controllers. I know Oak Technology, who is the market leader in CD-ROM controllers, is marketing both a DVD controller chip and a DVD decoder chip.
My understanding is that a DVD player would require both a controller chip and a decoder chip, while a DVD-ROM for PC would require a controller chip, but the decoder chip would be optional, since the MPEG-2 decoding could be done in software using the CPU. Whether that is an optimal design or merely a cost-saving measure, I don't know.
G.P. |
