Slashdot Mirror

I've never seen a NAND chip that does this. Ok, OneNand does something like this but it is not really for XIP, more it's a way to allow the ARM to be reading one buffer out of SRAM while another buffer is being fetched, i.e. it was a performance hack. You can XIP a bootstrap though, but only one page's worth. Of course you could use a demand paging scheme to execute larger applications, just like a normal NAND. Still OneNand isn't smart enough to do this without additional software support.

SST has had such a device out for a couple of years now:

http://www.sst.com/about_sst/news/detail.dot?crumbTitle=NewsDetail&id=361

Or at least it wasn't last time I checked. Mind you it could be done but if it was it means the hardware would need to handle bad blocks. Still you could just have a list of bad blocks/replacement blocks in some sort of TLB like content addressable memory and make sure any attempts to access them are redirected. From the devices I've used only around 1% of the blocks are potentially bad, so the CAM wouldn't have to be that large.

The SST device includes all of the hardware on chip to handle caching, ECC, and NAND Flash management so those operations are transparent. The on-chip static RAM is divided between program memory and XiP cache under user control.

Then again not doing this sort of thing in hardware is probably what makes NAND so cheap.

Actually I'm talking about mobile phones. They typically have quite a lot of flash memory - 128MB-512MB - above the point where NAND becomes cheaper than NOR. They also have a lot of SDRAM. All of this is offchip from the ARM.

The flash microcontrollers I've seen are 64K-256K and at that level NOR is apparently cheaper.

I gather from reading various trade articles on the subject that the motivation for XiP capability using Nand Flash is the density improvement. Single devices having separate Nor and Nand arrays for code and data respectively have been available for a long time but the Nor area penalty has become significantly enough to warrant significant complexity if it can be left out.

I suspect code shadowing is a better solution in most applications.

You could then pull the chip, and 'flag' the associated pins (bend them out, so they no longer enter the socket)

This is called "flying" a pin and its used frequently in debugging/modifying hardware. Good basic idea, but if you're going to attempt it, you'll need to tie it high as floating it will result in write cycles whenever the ambient RF decides to push your new "antenna" low. Most new bios uses a standard 1Mbit eeprom configuration (SGS datasheet here) so for the DIP configuration, write enable would be pin 31. Std procedure would be to tie it high through about a 10k resistor (ttl inputs can be damaged by power rail spikes if tied directly). Cut one lead of the resistor to about 1/4 inch length, tack solder it to the top of the (for now unbent) pin 31, stand the resistor vertically and loop the other lead over the top and down to the supply, pin 32. "Fly" the pin before reinserting or bend it back in to do flashing. The resistor remains. Find your specific mobo chip's datasheet here

i still watch my porn on betabax to get the high quality throbbing a porn connoisseur like myself demands. do you really think i'll switch to digital for my still action? doubtful.

on that note:
ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

"an african flavor to MySQL??"

seriously. WHAT THE FUCK.

the dolphins name is SQUEAL. EVERYONE thinks it should be SQUEAL. i am starting my own form of mysql starting today, and the ONLY thing different is that the dolphin is named SQUEAL!

on that note:
ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

come on, more like oranges to tangerines...

you are dealing with data instruction streams going on independantly, sure maybe only x2 or more with SMP, but x anything is infinately greater than x1 when dealing with threads.

and what is really the difference with oranges and tangerines? man i hate tangerines... if anything they are worse than oranges, but so similar. all tangerines should be destroyed. and thus i have proven why hyper-threading will fail.

on that note:
ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

i wonder if these business realize that they could have sold 1000 of these for $149 each if their site was up... advertising like this doesn't come around every day, and losing 150k just because you only wanted to pay $7.77 a month for web hosting is just sad.

on that note:
ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

seriously, don't buy cars there. i heard from some guy with a sign...

ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

of the time i saw this on the discovery channel over a year ago!

ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

now i'm just karma whoring... this is too easy

ARE YOU A PHP DEVELOPER? WORK WITH ME AND MAKE MILLIONS!
Web Developer II

RIAA Sues Radio Stations For Giving Away Free Music

ARE YOU A PHP DEVELOPER? WORK WITH ME ANE MAKE MILLIONS!
Web Developer II

this post isn't exactlly funny, and actually it will probably take much longer. producing 18 minutes of animation at TV scale takes them over 6 months. to do a movie will surely take over 2 years.

ARE YOU A PHP DEVELOPER? WORK WITH ME ANE MAKE MILLIONS!
Web Developer II

so... they are passing the bill of rights again? copyright law again?

we already can do this, just because the RIAA says we can't doesn't mean new legislation is required...

ARE YOU A PHP CODER? COME WORK WITH ME AND MAKE MILLIONS!
link to job description

i just gave my boss a gesture and now i'm looking for a new job. what do you think of this one? its in the bay area so i wouldn't have to move!

Web Developer II

too many words, i'll make it simple

BORG!

anyways, if you are a php developer, go here
WE ARE HIRING A DEVELOPER IN SUNNYVALE