"Antti Lukats" <antti@openchip.org> writes:> Creative lazyness and sometimes simple waiting (or sleeping) is possible the > most effective way to work!And it's a great weight loss program. You can burn 50-90 calories per hour sleeping. I think I'll start sleeping more!
Writing IP-Cores while sleeping ;)
Started by ●February 10, 2005
Reply by ●February 10, 20052005-02-10
Reply by ●February 10, 20052005-02-10
"Martin Schoeberl" <martin.schoeberl@chello.at> writes:> Sounds good. But these SD cards aren't they built with NAND Flash? > And NAND Flash can have bad sectors. If one of these bad sectors > is one of the first you can't use it.No, because the SD card incorporates an intelligent controller that hides the bad blocks, just like a SCSI disk does.
Reply by ●February 11, 20052005-02-11
"Antti Lukats" <antti@openchip.org> wrote in message news:cufkhe$mt7$03$1@news.t-online.com...> Hi > <snip FPGA bootloader for SD Card>Great, looks a very useful thing! Wouldn't this be better done by a small micro (e.g. AVR) though? These could be smaller than the 9536 chips. I'm also looking for a system where the main micro can use the SD card after booting. That is, the FPGA boot device tri-states the control signals so the main CPU can drive them. This would get more usefulness out of the SD card. However, if the card gets the FPGA bit file re-written on a PC then returned, the CPLD hardware method might have to send megabytes of data before the FPGA sees the sync word. A micro-based method might be able to search a FAT to find a particular-named file, though obviously this is a non-trivial job unless you have some experience with FAT already. Anyone got any PD FAT source code in C?
Reply by ●February 11, 20052005-02-11
In article <mr3Pd.585$ss.29@newsfe1-gui.ntli.net>, Kryten wrote:> > However, if the card gets the FPGA bit file re-written on a PC then > returned, the CPLD hardware method might have to send megabytes of data > before the FPGA sees the sync word. A micro-based method might be able to > search a FAT to find a particular-named file, though obviously this is a > non-trivial job unless you have some experience with FAT already. Anyone got > any PD FAT source code in C?I'm sure there are others, but OpenDOS, OpenBSD, NetBSD, FreeBSD, Linux, and such do have farious versions of FAT code. Also, I seem to remember a number of MP3 type projects out there with FAT code. -- [100~Plax]sb16i0A2172656B63616820636420726568746F6E61207473754A[dZ1!=b]salax
Reply by ●February 11, 20052005-02-11
Antti Lukats wrote:> <snip FPGA bootloader for SD Card>Kryten wrote:> Wouldn't this be better done by a small micro (e.g. AVR) though?It could be, but it would be slower and more expensive.> These could be smaller than the 9536 chips.The 9536XL is amazingly cheap.> I'm also looking for a system where the main micro can use the SD card after > booting.Shouldn't be any problem with that. Just tie the SD to both the CPLD (or uP) and the FPGA, and have the CPLD (or uP) put its SD interface pins into high-Z once the config is done.> However, if the card gets the FPGA bit file re-written on a PC then > returned, the CPLD hardware method might have to send megabytes of data > before the FPGA sees the sync word. A micro-based method might be able to > search a FAT to find a particular-named file,True. A point in favor of the microcontroller. Though if you don't mind writing special code for the PC, you can have it always arrange for the FPGA bit file to be a single contiguous chunk near the start of the SD. In fact, once you've got it there the first time, you should be able to rewrite the bit file without it moving around.> though obviously this is a > non-trivial job unless you have some experience with FAT already. Anyone got > any PD FAT source code in C?Yes, RDCF2 by Philip J. Erdelsky: http://alumnus.caltech.edu/~pje/rdcf2.txt I wish I'd known about RDCF2 when I wrote the boot ROM for the ReplayTV. I wrote my own read-only FAT filesystem for it. (Used for software development only; the ReplayTV does not use FAT.) Eric
Reply by ●February 11, 20052005-02-11
Kryten wrote:> Anyone got any PD FAT source code in C?Tobias Weingartner wrote:> I'm sure there are others, but OpenDOS, OpenBSD, NetBSD, FreeBSD, Linux, > and such do have farious versions of FAT code.None of which are public domain. The BSD licensed code is closest. But code for either a BSD or Linux kernel will be hard to adapt to a tiny microcontroller.
