Re: bit errors on spitz

From: Andy Green
Date: Thu Mar 11 2010 - 16:21:47 EST


On 03/11/10 15:42, Somebody in the thread at some point said:
Andy Green wrote:

I saw very similar failures for a long time on our iMX31 based device.
Eventually I found a Freescale errata where the RAM inside the USB2
macrocell started to make single bit errors below 1.38V Vcore; ours was
1.4V at that time but dipped on CPU load.

Good tip. It seems that nobody ported driver for the voltage control
chip ISL6271 from 2.4 kernel, and bootloader probably does not set
correct values.

Datasheet:
http://www.penguin.cz/~utx/zaurus/datasheets/power/Xscale/ISL6271.pdf

Unless there's more to it in the way the zaurus using it that regulator isn't programmable digitally.

Reading about your CF Card WLAN related issues they suck down a good amount of power when their radio is up, I would definitely suggest monitoring with a 'scope the various rails (Vcore, RAM and whatever it is the CF Card is powered by) while putting it under load.

-Andy
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