Industry Expert Blogs
Low Power, Phones, Tablets and PCIe, Oh My!Express Yourself - Scott KnowltonMay. 22, 2015 |
First, I’m sure there are some of you that look at this and think “what the heck”? PCIe being used in phones and tablet devices? How can that be? Rest assured PCIe has been used in mobile devices for a long time. Of course, laptops have been using it, but it’s also being used in phones and tablets for some time now. You may remember that PCIe with the MIPI M-PHY and say, that’s what Scott’s talking about, but no. This is the full blown PCI Express in these devices operating at 5.0GT/s and 8GT/s.
Who wants to put a PCIe PHY developed for driving backplanes and across multiple connectors into a phone? Good question! The ability to do this really comes down to managing the power in the PHY and controller in coordination with the rest of the chip design connected to a small channel. Of course, L1 substates was a huge stride to get you there, but the power needs to be reduced even further. Nobody wants their phone or tablet using up power when you are not using it, just to be dead when you need it. The interface needs to be completely off and this can be done when using L1 substates in conjunction with power gating techniques.