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Hey,
we have developed a board based on AT91SAM9263 and with Adeneo BSP on Windows CE 6.0.
Everything was fine, till now. We sell devices (Terminals) for about a year, and now comes a sudden reset during normal usage.
We have two kind of terminals, one with a large display with CCFL inverter for background light, and one with a small display with LED background light. The smaller terminals have not bluetooth, nor WLAN possibility, either (but his is just two devices behind an USB HUBon the baseboard).
We have the same kernel for both devices, running on 200 MHz core clock, and 100 MHz master clock.
So the reset occures JUST on the smaller terminal, with normal usage.
We have made some experimentation, and if we are cooling with spray our processor board downto about minus 30-40 C, on both terminal the same effect, resetting accidentally. (Processor, SDRAM, NAND Flash, and 5->3 supply on it, all the parts with industrial temperature range).
After bootup i read the reset controller status register, says "General Reset", but the power supply both on VDDCORE and VDDBU was stable, just the NRST went down. NRST is connected with some slave peripheries, but this signal can not be output on these parts, so i assume, the Atmel pull it down himself. HW watchdog is deactivated in OEMInit.
In the bigger terminal is higher temperature (because of the inverter for light), and if the houseing is closed, this reset does not occure, so i suppose, the clock (PLL) is sensible for temperature.
We have found a workaround, if we set the clock to 240/60 MHz, it does not matter what we do (cooling, hard processor usage) it does not resetting itself. Reset occures on 160/80, too. According to processor datasheet, we can not use 240/120 because of SDRAM controller absolute maximum rating, can we?! But this 240/60 seting is a decline, and for example for the bigger display we can not set the 25.125 MHz (21-29) so precise, and thatswhy there is malfunction sometimes...
Does anybody have any idea?
Thanks in advance!
Zsolt Talaber
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