DRAM Defect in Some Palm, TRGpro, and Visor Models

Palm is making available a software patch to address a faulty 8MB DRAM component identified in a limited run of Palm IIIc, IIIxe, and Vx products manufactured between the period of October 1999 through May 2000. Palm uses multiple sources for these DRAMs in the manufacturing process. One of the suppliers of DRAM components provided Palm with a faulty component that can cause random data to be written on the Palm device. If a unit is determined to have the faulty chip, the software patch will provide a complete fix.

A majority of Palm handhelds are free of the defect, including all 2MB, 4MB and most 8MB units.

TRG is also acknowledging that some of their units are also affected by the defect and suggests that all users affected upgrade to Palm OS 3.5.1, which is free. If you don't want to upgrade, TRG will soon be offering a patch for OS 3.3.

And now Visor has stepped forward to state that they, too, are affected. The majority of Visor handhelds are free of the 8MB DRAM issue, including all 2MB Visor Solo and most 8MB Visor Deluxe units. Only a limited number of Visor Deluxe handhelds shipped between the period of January 2000 to June 2000 may be affected with this faulty chip. Visor is offering a test app to look for the defect but currently just suggests you contact tech support if you discover your Visor is affected.

TRG is offering the following technical description of the problem:

Q: What causes the DRAM problem?
A: The exiting of self-refresh mode on a certain vendor's DRAM was not implemented correctly. This can cause a portion of memory to become corrupted.
Details: The Palm OS goes to sleep and wakes up once every minute to perform some housekeeping functions. This, in turn, causes the DRAM to enter and exit self-refresh mode once per minute. Since self-refresh mode is flawed in certain vendor's DRAMs, there is a chance for data corruption to occur every time self-refresh mode is exited on units which use that vendor's DRAMs.

Q: What is DRAM self-refresh mode?
A: When your unit is on, the processor is responsible for maintaining the contents of DRAM. When the unit is "off", the processor is shut down and the DRAM is commanded to assume responsibility for its own refresh. This mode is called DRAM self-refresh.

Q: How likely is the failure to occur?
A: If your unit contains the faulty DRAM, it is a statistical certainty given infinite time.
Details: Through testing, TRG has observed that there is about a 1/8000 chance of a row of data (2K) being corrupted every time self-refresh is exited. In a 24 hour period, the TRGpro will wake up 1440 times. In 5.5 days, the unit will experience 8000 wake / sleep cycles. If a corruption occurs in an area of memory that is in use, you will experience the problem. Since the location of the failure in memory is random, your odds of detecting the failure will increase with the amount of memory you use.

Q: How can software fix this problem?
A: TRG developed a work-around which does not put the DRAM into self-refresh mode. If self-refresh mode is not used, the problem will not occur.
Details: TRG refreshes the DRAM using a technique called "burst CBR refresh". This avoids the need to enter/exit self-refresh mode.

Q: How did TRG discover this problem?
A: TRG was testing a change to Palm OS3.5 that required the unit to wake up once every 5 seconds instead of once per minute. This increased the chances of the failure occurring by 12x. With the help of TRG's beta testers, the problem was then detected and isolated to a particular vendor's DRAM. TRG then reported the problem to the DRAM manufacturer and developed the fix.

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How about Vx?

I.M. Anonymous @ 6/29/2000 3:52:59 PM #
Can I run the TRG OS3.5.1 upgrade on my Vx?
Do I even WANT to upgrade my Vx to OS 3.5 (I have OS 3.3 now)
RE: How about Vx?
ed@palminfocenter.com @ 6/30/2000 8:41:50 AM #
I don't know for sure, but I suspect that you can't upgrade a Palm Vx with TRG software. I suggest you ask this question on the Experts Exchange:

http://www.experts-exchange.com/Computers/PDA/Palm_Pilot/" CLASS=NEWS TARGET=_NEW>http://www.experts-exchange.com/Computers/PDA/Palm_Pilot/

RE: How about Vx?
I.M. Anonymous @ 7/3/2000 12:21:42 PM #
Don't think it'll work, HOWEVER, Palm's fix is quite effective.
I just recieved an "Advance exchange" Vx (My original one was damaged) that DID have the faulty DRAM. Upgraded just fine. Now, I'm re-installing (one at a time) some of the old apps I thought were responsible for crashing my device.

How about the upgraded V's?

void @ 6/30/2000 4:16:21 AM #
I have a V that was upgraded last september. Is there any way of knowing if I have a faulty chip?
RE: How about the upgraded V's?
ed@palminfocenter.com @ 6/30/2000 8:33:00 AM #
September is outside the time frame that Palm is saying that bad parts were used. Odds are your handheld is fine, unless you've noticed frequent unexplained crashes.

How about PalmIIIxe

Viktor @ 6/30/2000 4:30:08 AM #
I have PalmIIIxe with OS3.5.
What can I do?
RE: How about PalmIIIxe
ed@palminfocenter.com @ 6/30/2000 8:29:48 AM #
Palm, Inc. is currently developing a software patch specifically for the Palm IIIxe. Once this patch is available, information will be posted to the the 8MB DRAM issue web site.

http://www.palm.com/support/dram/" CLASS=NEWS TARGET=_NEW>http://www.palm.com/support/dram/

There is a form on the following page where you can put in your e-mail address and Palm will notify you when the patch is finished.

http://palmsupport.conxion.com/dram_3xe.html" CLASS=NEWS TARGET=_NEW>http://palmsupport.conxion.com/dram_3xe.html

And the Culprit is...

ed@palminfocenter.com @ 6/30/2000 1:19:46 PM #
A spokesman for Micron Technology Inc. confirmed that the DRAMs involved in the Palm PDA problem were supplied by them. He said the company discovered during an accelerated testing procedure an infrequent DRAM timing issue that occurred in rare instances as a part of the system software and application operation.

"Micron notified Palm immediately and worked in close cooperation to develop a software fix," he said.

Micron pointed out that its DRAM chip itself wasn't defective, since the chip isn't being replaced. He also said that Micron notified all OEM customers of the chip about the problem, "but no one else has indicated they have any trouble."



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