as always, MS has patents for obvious things. Slightly bad news, fortunately VFAT or exFAT needed for Windows communication by via card only. So long file name support really do not have be realised if we count using card exlusively inside embedded system.
and yes, the file size in directory entries for files is needed because although we have a fixed amount of storage space allocated, the actual file will probably be smaller and hence we need to know where it actually ends.
Thanks everyone for attending, I hope to see you again tommorow for the lecture titled "Balancing Performance, Safety and Resource Usage in an Embedded System".
Mark1200: yes, you are right, the first LFN entry is the one that immediately precedes the normal directory entry. The last one is the first that appears in the directory table and it has a specific bit in the sequence number that indicates that it's the last entry.
gbegin: it's actually not CRC, but a checksum of the DOS (8.3) filename, so that it can make sure that the LFN directory entry really goes with a specific normal directory entry.
Atlant: they're using some workarounds that they claim does not infringe Microsoft's patents. Microsoft did go after linux-based products (TomTom), however.
mharkins: It's hard to say if exFat will get widely adopted. For now, its adoption is slow, but with the Secure Digital Association adopting exFAT as its recommended file system for SDXC cards, it might become more widespread.
Altant: yes, NAND flashes have a spare area that can (and must...) be used for Error Correction Codes (ECC). Without those, you can expect your file system to become corrupted really fast. HDDS also have OOB storage for ECC, but that's all hidden by the controller.
srdmahesh: It would depend on your application, if you need to interoperate with a desktop PC either through a removable media or through USB Mass Storage Device Class, having FAT is certainly a good bet. If that's not required, FAT might still be a good choice since it's relatively lightweight. Also, some journaling add-ons can make it more reliable and protect it from unexpected power-losses on embedded systems where you're exposed to unexpected power-losses
The low level disk interfaces save track/sector and crc for each sector as part of the magnetic patterns, historically. So for data integrity, something like that would need to wrap the data when saved to EEPROM or Flash.
@Eric. Well, how likely is it for SD cards to move to exFat then? (Or do I need to plan on re-writting the FAT32 embedded code I'm just getting ready to release!
In our case, *CERTAIN MODELS* of USB sticks were indicating that they had finished writing before they actually had, so the power-cut that followed was causing the last several writes to not actually get committed to the Flash media inside the USB stick. This led to corrupted FAT32 file systems.
answer to file size why needed is that the bytes in a file may not be the same as the bytes available in a sector so an exact file size would be needed.
@levitonDave LOL Speak for yourself :) We've had some where we live in Gresham. But I agree, nothing like what's going on in the midwest and back east.
The streaming audio player will appear on this web page when the show starts at 2pm eastern today. Note however that some companies block live audio streams. If when the show starts you don't hear any audio, try refreshing your browser.
@vsrollins - you have my sympathy. I moved away from Milwaukee to get away from the snow. Portland really doesn't see much of that (none for the year :) )
The downloads for Wed-Fri have mis-coded links. I was able to hand edit the URL to match today's version style/base . Then they downloaded and converted fine.
By experimenting with the photovoltaic reaction in solar cells, researchers at MIT have made a breakthrough in energy efficiency that significantly pushes the boundaries of current commercial cells on the market.
In a world that's going green, industrial operations have a problem: Their processes involve materials that are potentially toxic, flammable, corrosive, or reactive. If improperly managed, this can precipitate dangerous health and environmental consequences.
With LEDs dropping in price virtually every year, automakers have begun employing them, not only on luxury vehicles, but on entry-level models, as well.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 4
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
3 
