If you’re on LinkedIn, check out the Realtime Embedded Engineering Group for an interesting and often lively discussion of the issues facing our community. We particularly enjoyed reading the recent thread about the drivers included by hardware vendors being less than optimal for most flash parts. The consensus can be summed up in one blogger’s statement;

“What many silicon vendors refer to as a ‘driver’ is nothing more than the code left over by their inhouse hardware development team. This code typically exercises just a small subset of the device capabilities (or whatever they were working on last) and doesn’t even come close to meeting the definition (or spirit) of a general purpose device driver.”

We couldn’t have said it better ourselves. A lot of our time in developing our FlashFX family of flash memory drivers is spent ensuring completeness, reliability and portability to a wide variety of CPUs and operating systems.

Watch Rob Hart demonstrating the Datalight flash file system on the Beagle Board with Windows CE 6.0

Last week one of our customers sent the following evaluation report in an email to Datalight support staff:

“Right now we are in the process of testing the impact of Reliance Nitro in our application. Apparently, we noticed some boost in the performance:  faster write speed, significant speed increase of transaction point creation, faster read speed, and significantly faster directory read (we typically have 1000 files in the directory). So, in conclusion, the overall performance of the system is boosted quite significantly.”

Another real world example of how Reliance Nitro boosts performance in directories with a large number of files. To learn how Reliance Nitro does it, check out the whitepaper.

Palm just announced the 1.1 update to its popular WebOS that runs on the Palm Pre device. Apple released the 3.0 update to its Mac OSX for the iPhone and iPod touch. Microsoft is expected to launch Windows Mobile 6.5 soon and users are hoping that they will be able to update their 6.1 devices to 6.5. Google last month updated Android OS to 1.5. These events point to a recent and very fast growing phenomena: embedded devices are becoming more and more like PCs where users expect to be able to update their device long after it has been released. This was not always the case; OEMs refrained from updating embedded devices unless in cases of high severity bug fixes. There are several reasons for this:

1. Updating embedded devices is more difficult than updating PCs from a distribution standpoint
2. Because of #1, updating devices is also expensive
3. Potential of bricking devices (device does not boot anymore) due to user error is very high leading to high risk of warranty returns 

Today’s blog post focuses on #3 because it has very real technical risks and solutions. Before we begin discussing risks of bricking device, let’s talk about 2 different types of updates 

1. Update to application code – This is usually much simpler and does not typically involve changes to the bootloader or the boot image
2. Update to system code/OS image – most of the times when OEMs have to update devices, it is due to some severe error. In our experience it usually involves changing system files. If the entire OS is stored as a single image on disk/flash, then entire image has to be correctly replaced with the new one

If the update is of type 1, then the process has less likelihood of bricking the device. In most cases even if the update fails, support can help user start the device in “safe” mode and restore. Updates of type 2 are by nature riskier because any failure is likely to stop the device from booting up, negating any remote debugging options. Note that It is also possible that for some devices, the application and system code is stored in single boot image. In that case, the distinction of types made above are irrelevant for this discussion. 

OS/System Updates 

Here is how devices typically partition the data storage for boot and application data

Note: Some devices may not use the file system for the boot partition and instead directly talk to the block device. In that case, the remainder of this discussion is not applicable.

During an update process involving system code, the boot image has to be replaced with a  new one. Typically the update process will overwrite the existing image. The problem happens when the update process is interrupted due to erroneous circumstances such as 

1. Device battery dies before the update process is completed
2. The user pulls out the USB cord connecting the device to host

 In these cases, the OS image will get corrupted and the device may not be able to boot back up, leading to a bricked device.

 One of the features of Reliance (and Reliance Nitro) file system is that it never overwrites live data. It will always use free space on disk or in case there is no space, it will give “disk full” error back to the application. Reliance also has a special transaction mode called “Application-controlled”. In this case, Reliance only conducts a transaction point when asked by the application. Here is how these 2 constructs help Reliance provide a fail-safe means of in-place updates

1. The OS image is stored on a Reliance partition
2. The update application calls Reliance API to disable all transaction modes. Reliance will now execute a transaction point only when specifically called by the update app
3. The update app starts “overwriting” the existing OS image. Because Reliance never overwrites live data, it will start copying the new image to free space on disk
4. In case power is interrupted, Reliance discards the new image and device can still boot back to the old OS image and restart the update process
5. Once the entire update process is completed, the update app calls Reliance to execute a transaction point. Reliance, in one atomic operation, updates its committed state to now use the new image. When the device boots back up, it now uses the new image. The old image is now marked as free space by the file system

Using Reliance for boot partition can thus help in providing a safe in-place update process. It also has the advantage of using Reliance extreme fast mount times, which can help in speeding device boot speeds.

Note that the obvious caveat of the above is that there has to enough free space for the new OS image. With disk storage being cheap (compared to device cost) and always increasing, this becomes less and less of an issue. OEMs should strongly consider going this alternative (whether they use Reliance or not) in order to ensure that the device update process will go smoothly for the end users.

It’s been over 20 years since NAND flash was supposed to take over the world, so why is the ‘ultra-portable’ laptop I’m writing this on still using HDD? And why, nearly 30 years after the invention of flash, are we still debating its applications vs. the rotating platter? Given the performance advantages of flash and the mechanical shortcomings of HDD – things like wear and susceptibility to shock and vibration, not to mention the latency associated with spinning up for reads – it’s no wonder that flash has long been the darling of memory technology futurists. So why after all this time has flash not replaced older technologies? I’ll give you a hint: It’s all about the money. But it’s not only about the money – check out our list of five top barriers to flash adoption:

1. Cost – Despite years of oversupply in the flash market, and the corresponding reductions in price, flash is still relatively expensive when compared to HDD, especially on a $/bit basis. To make matters worse, the current economic climate has taken its toll on the flash industry, spurring several rounds of consolidation and requiring flash vendors to curb manufacturing costs by shrinking portfolios and closing fabs. Predictably, these changes in the supply landscape are causing prices rise in many cases, making the cost factor an even bigger problem for flash.

2. Shrinking lithography = lower endurance – One way for flash manufacturers to remain competitive is to use smaller die size to reduce raw material costs. Just a couple years ago, the vast majority of NAND flash was manufactured with 90nm lithography. Most vendors are now planning to move to 30nm technology either this year or next. An unfortunate side-effect of smaller lithography is significantly decreased endurance. SLC NAND, which had 100K + erase cycles, is now predicted to be in the 50-70k range. The biggest impact is on MLC NAND where the endurance has gone from 10k erase cycles to around 3k (a 70% reduction!).

3. Increasing ECC – Another side-effect of shrinking lithography is an increase in error rates for flash, requiring stronger correction codes. Most SLC NAND flash today requires 1-bit correction. That number is predicted to increase to 4-bit on 30nm NOR parts. And the ECC outlook for MLC NAND is even worse, requiring ECCs greater than 12-bit (compared to 4-bit or 8-bit today). These increased ECC requirements mean the controller design for managing flash will become more complicated, and more difficult for OEMs to implement. Performance will also be impacted, especially if the ECC is done in software running on the host processor.

4. Vendor volatility – Churn or volatility in the flash market, the products of a difficult economic climate, are making it difficult for OEMs to find a reliable source of flash parts. Examples are everywhere; A major flash supplier is currently under Chapter 11. There are merger talks happening between SanDisk and Samsung. Asian vendors have been hit especially hard, particularly those also in the DRAM business. OEMs are rightfully concerned about interruptions to their production cycles in the midst of all this turmoil.

5. Lack of killer application – While NAND flash densities have continued to increase, the industry is still waiting for the killer application to gobble up these immense quantities of flash. For long SSDs have been viewed as that application but they have not taken off as fast as the flash industry would have liked.

In spite of the obstacles faced by the industry, flash remains a strong and growing choice for data storage and has put breakthrough devices like MP3 players and smart phones (iPhone!) into the hands of millions of consumers. Early adopters of SSD technology in laptop computers, netbooks and enterprise applications are making a solid case for mass market potential there, which should significantly drive flash adoption in the next few years. Visit the FlashFX Tera page to learn how Datalight is making flash easier and more competitive.

Our R&D folks couldn’t wait to get their hands on the new test board from Digi which arrived a couple weeks ago. The board comes with multiple testing interfaces, making it easy to switch between a number of different flash parts for back-to-back comparisons. They have been practically wearing the thing out, testing the performance of a number of different managed and raw NAND parts to get a better idea of the differences our customers see when doing benchmarks. Check out a few pictures of the setup currently in Glenn’s office, and contact us for more information on this project.

Ever since we announced our high performance file system Reliance Nitro, we have been getting questions on how it compares to the original Reliance file system. Below is a quick-reference table noting some of the differences between the two. For a more detailed comparison (including performance benchmarks), please contact us.

With the release of our new file system this week, Reliance Nitro, we asked our Account Managers what they liked most about our new product. Their answers of course included reliability and high performance. Wes Johns and Phillip Allison were so excited they decided to make a video…  watch the youtube video

We’re totally psyched about Reliance Nitro, our newest file system (yes, we’re file geeks), and we’re always on the lookout for opportunities to show off the performance and reliability attributes it adds to Windows Mobile and Windows CE. When we discovered the relatively-new Beagle Board, it occurred to us that a small, low-cost platform might be just the thing to demonstrate Nitro’s amazing benefits. As you’ve probably heard, the Beagle is making waves with its low cost (around $150) and diminutive size. It uses an OMAP 3530 processor and 256MB of NAND. Though they are most commonly used with Linux, we lucked out in having a partner (MPC Data) who has already developed a Windows CE BSP for it. After a few phone calls, the wizards at MPC Data were able to develop a slick video playback demo app, and presto, the Reliance Nitro Beagle Demo was born! Amateur videographers that we are (ok, REALLY amateur), we recently videotaped John Burnham, who has been working on this project on the Datalight side (and who is a really good sport, btw) showing what happens when power is interrupted during a file write and the extra reliability factor of Reliance Nitro on Windows CE. Be sure to check it out here.

Sea Change Hits Consumer Electronics as Customers Demand Long-term Value

For the first time in more than a decade, people are saving again. In 2007 and years prior, the savings rate hovered around zero as we maxed our credit cards and lines of credit, driving the savings rate into the red and giving the world’s manufacturing base an almost unbelievable boom. In January 2009 though, something unexpected happened; the US savings rate suddenly moved above 5%, the highest in decades. As news of our cloudy economic picture has emerged, consumer behavior is shifting away from status-seeking luxury purchases toward more value-based buying patterns, forcing manufacturers around the world to take notice. And after decades of excess, the shift to thrift is looking like a lasting trend.

But what does this mean for Embedded? As consumers focus on needs over wants, they will increasingly seek out products that are proven durable and reliable.

This will have broad implications for manufacturers of everything from cars to clothing, refrigerators to embedded devices. Today’s consumers are choosing efficiency, durability and value over gee-whiz gadgetry. Consumer mobile OEMs too must focus on delivering value and fewer, more targeted features. Rather than packing devices full of a laundry list of apps and expensive hardware, this means streamlined offerings and more segmented products, while making sure the consumer doesn’t feel like they’re missing out. Motorola’s new EM330 is a prime example of this kind of pared-down, demographic-specific approach. The phone, called the MOTOROKR STAR is marketed specifically toward music lovers, offering a basic clamshell with music recognition software and download-on-the-go at a price point in the sub-$200 range.

As OEMs scramble to add value and enhance their reputations for durability and reliability, Datalight responds with products that support those goals. The combination of flexible flash management that lowers bill of material costs, wear-leveling algorithms extend flash life by several times, and the rock-solid reliability of our file system become essential components of a strategy to provide value to customers.

Many have remarked that markets are driven by a combination of fear and greed. Though the pendulum has recently taken a dramatic –and we believe temporary– move in the direction of fear, ultimately we know a move away from excess is good for all of us and good for the world we live in. Here’s hoping the trend toward value and quality is a long-lasting one.