S1 EP28 - Read Channel Innovations

discussion today. I'd like to start off with just establishing what is read channel.

protection techniques. Marvell's advanced architecture really allows the customers to achieve best in class areal density, data reliability, and power consumption in order to effectively meet the growing demand for storing more and more data. And always data stored on the on the hard disk drive what's really stored on magnetic disks, that's kind of mini magnets that really points up or

down from the disk. And basically, magnet pointing up representative one and magnets pointing down represents a zero. And the writing process goes to have a right hand that tries to magnetize the media in this direction. So basically, if we want to write one by one it point up. And if you want to write a zero, maybe it point down. And then we come back and

read this data. And then it's a READ sensor that passes over the data and senses the magnetic fields on these magnets and basically returns in electrical signals, this electro signals goes through a preamplifier and then into the READ Channel of and then the purpose will read channels to accurately decode this data and return it to the user.

And this is really expected to grow to over 40 terabytes by the end of the decade, if not before them. So basically, what we have to do is we have the squeeze in more data per desk. And if possible, more disks per drive. Getting more disk drive, you're limited by the form factor of the drive. Drive is roughly one inch high in the data centers. And how many disks can you squeeze into that. Right now, It's about 10, trying to squeeze in maybe 12. But seems like that

may be a limit. But of course, you can't really make the disks and the bigger because once again, the form factor of three and a half inch disks if you want to make them bigger, you will actually need to change the form factor in the data centers. But the other thing, of course, to add additional capacity is to increase the areal density. That's basically number of beds you fit to desk or to give an area of the desk. Of course, when you do that, it makes it a little bit harder to reliably

read back during the day. So the main challenge for the READ Channel is to really continue to improve the performance year after year. And one of the interesting aspects of the READ Channel is also that it's a closed system to the best of the READ Channel both write the data to the disk and reads back the data from the same disk. So there's no standards limits innovation for us.

development. For example, at Marvell, we utilize machine learning techniques several years ago, that was prohibitively complex to implement and utilize that mainly for kind of guiding development, what can we do? Recently, we've utilized machine learning techniques to provide additional gains with, for example, nonlinear equalization. You know Chris, one of our engineers won the “Best poster presentation award", at the recent Magnetic Recording Conference, or also known as

TMRC, back in August. And in addition, we're also looking to kind of develop better air control code such as LDPC codes and aura codes, to bring us to the next capacity gains. So machine learning is a big thing in the future. And we're also looking to develop better error control codes such as PC codes, and we're looking into polar codes as well. Well, there's a lot of lot of interesting challenges going on.

temperature. But then when you heat them up, or excited with a microwaves, they get easier to flip to do this in the right process example, you have a laser spot, you heat up the spot where you want to write, and then you can write a bit of the bits there. And then when the laser passes by, the media cools down and immediately stable. So this is what kind of the companies are looking at now and

in the future. And trying to really make this into markets, which will help us achieve this 40 a terabyte and talking about even 50 terabyte drives in the future. So this is kind of an exciting time in this area.