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Step into any Starbucks hotspot or Wi-Fi cafe, and you'll see something that was unthought of just 10 years ago: people working on laptops, accessing wireless internet at broadband speeds. I don't know about you, but to me, that is simply amazing. Imagine, 10 years ago we would have been content with surfing the internet at 56k dialup speeds. Now, we've come to expect consistently fast broadband speeds. If a website takes more than 5 seconds to load, immediately we think something's wrong with the connection.
So are we in wireless utopia? Apparently the answer is not yet. The ideal situation would be where you could access high-quality broadband anytime, anywhere. This requires a wireless data protocol that has greater range. The WiMAX standard is a step in that direction. With a 50km/30miles max range, it promises to take broadband wireless data a step beyond what's capable today. Of course, the closer you are to the 30 mile max range, the worse your reception and speed is going to be. But the potential is there. That is why manufacturers are recognizing WiMAX to be a step in the right direction.
Sequans is one of the innovators in the WiMAX field. Recently they introduced their SQN1210 WiMAX chip at the Mobile World Congress in Barcelona in March. Some specifications: Baseband and triple RF on a single die; 350W @ 600MHz with fully loaded MIMO traffic, and less than 0.5W in sleep mode. It also has it's own built-in SDRAM, eliminating the need for external memory banks. These specifications are actually pretty impressive, as they offer not only savings in system/die area ($$), but also the high performance needed for mobile applications going forward, and of course the ability to stick withint he system's power budget to operate for a long period of time on batteries.
The question is: what technological feats did Sequans have to pull off, in order to achieve the above? One of the things Sequans designers did for this design, was to employ power shutoff (PSO) in their design. Another was to utilize multiple supply voltages (or MSV for short). The combination of these two advanced low power techniques meant that Sequans had to work with the multiple power domains throughout their entire design flow. The Cadence Low Power Solution was used for this task, including Encounter Digital Implementation System for the physical implementation for the design.
You can read more about Sequans' tapeout at this link:
Regarding the actual design flow of low power chips: the ability to simulate power switches in your design from the start, even without having them in your RTL, is very handy. RTL today usually doesn't have power switches, in order to retain the re-usability of the RTL, but we still need a way to simulate RTL with the knowledge that eventually, power switches will enter the netlist. During the physical implementation stage, more automation is always better. Physical designers already have too many items to worry about (dont' we all). Having the tool handle all the intricacies of power domains automatically so that designers can focus on design issues has always been appealing. In addition, before the chip tapes out, there has to be a systematic way of checking out and signing off everything related to the low power techniques in use: power switches placed in the correct locations, sleep signals corrected correctly, power nets connected correctly... the list goes on. As you can see, the tasks Sequans designers overcame, were pretty significant.
So, if everything goes well for Sequans and the WiMAX industry in general, maybe our days of putting "I am on vacation and will be out of e-mail contact" in our out-of-office messages are numbered... but on the bright side, we would also be able to run remote sessions of Encounter while sitting at the beach... how about that!
Wei Lii Tan
Cadence Design Systems