For my first blog, I wanted to follow up on today’s press release by delving a little more into what exactly our SDIO-EBI2 solution does for customers.
The primary benefit is connectivity efficiency. In most instances, the modem chip set ‘talks’ with the applications processor through USB…and that solution works OK. But it can be done better, especially in the area of power efficiency. Two chips talking to each other over USB requires multiple USB PHYs to be active, which as any electrical engineer will tell you, isn’t exactly low power (especially for battery powered devices) — each USB connection can consume over 100mW. The QuickLogic solution enables communication using the SDIO port of the applications processor and the EBI2 port of the Qualcomm cellular modem chip sets in a much more power efficient way. This efficiency is immediate, as you are saving power anytime the device is communicating by modem as compared to USB communication. And judging by my last bill…my phone is communicating a LOT by modem.
Secondarily, this also frees up USB controllers on the apps processor. Even today, the amount of USB controllers on the applications processor are sometimes just enough to meet internal communication demands plus a port for sideloading and battery charging. Often times, there aren’t enough controllers to satisfy demand, especially in newer smartphones full of bells and whistles (metaphorically full…but who knows what might be just around the bend?). The SDIO to EDI2 solution frees up a USB controllers in this case for other demands.
An alternative architecture in a system with a full USB load would be the addition of an external USB hub chip (a 1 to 3 splitter, for instance). The QuickLogic CSSP PolarPro-based SDIO to EBI2 solution will be cheaper than this alternative, certainly more power efficient, and likely would offer a smaller footprint. Plus, the SDIO to EBI2 solution doesn’t exhaust all the available fabric space in the PolarPro device, allowing additional PSB technology(s) to be loaded to further improve system design or user experience.
Will this feature eliminate USB as the choice of internal interface on devices? Our CX line of platforms has USB 2.0 as a communication method (along with ULPI and HSI, but that’s for another blog, another day), so it would stand to reason we are sure the answer is no. USB remains the interface of choice for its relative ease-of-integration, industry support, and design engineer knowledge base. What the SDIO-EBI2 solution presents is an option for power for USB slot-strapped system designers to make their systems better with a minimum of design work, using a proven technology from QuickLogic.
And hey…we even provide the software drivers for a Linux & Windows Mobile OS, customized to the OEMs needs.
2 thoughts on “Increasing Connectivity Through Alternative Interfaces”
Mehul: Thanks for the post. Can you quantify a little bit the power savings of the interface vs USB? How much (in terms of %) would this add to battery life for a “normal user” today and what is envisioned tomorrow? Also, can you quantify savings with this alternative and smaller footprint? How much could this reduce the total cost or total BOM? Also, what PSB’s could be added in the available fabric space of the PolarPro device?
Was this the result of Quicklogic engineers trying to design better solutions, or were customers or prospective customers asking you to do this? Thanks and best of luck. Steve
Thanks for the question Steve. That is a complex question since it depends on relative energy between the USB system and the rest of the system. So for example, a typical processor might consume 700mW when running, and we know that a USB modem draws maybe 2.5W (right at the power limit for USB). So switching to SDIO would drop that to 2.4W, so total system power would drop from 3.2W to 3.1W which is about 3%. But the modem radio is probably not running all the time, so if we assume that it is running 5% of the time, and we guess that it is 2W, then the average for the modem is 600mW, so now total power goes from 1.3W to 1.2W, which is 8%, or about ½ hour added on to an 8 hour shift.
With regards to footprint external USB controllers and hubs can be 5x5mm or more so the savings can be substantial since our solution is available in a WLCSP. The cost is also cheaper as our solution does not require a PHY.
The solution was a result of a little bit of both. We were working on a solution for a prospective customer and we thought that this solution can provide additional benefit in other applications too.
Once again thanks for your interest.