AM3505 low temperature problem

Other Parts Discussed in Thread: AM3505

Hello everyone,

         We have a very strange temperature problem for AM3505 need to your help,our system is Android2.3.4(kernel 2.6.37)

         We product 27pcs AM3505 broads on last week, But we have found 12pcs board can't run successful(the system will hung up) under 5℃,follow table is our test result:

       The x-loader and uboot are run ok on those problem's board in most of time, and that's  hung up the start run kernel time in most of time,the system will not reponse for ever after print "Uncompressing Linux... done,booting the kernel".

       We have taken something steps to debug this problem,but still can't find out exact reasons,the follows was our steps:

 Software:

      1.Because the logo screen will can't display normally on issue time. so i according this feature to debug out the problem place, i found the most of problem board will hung up the "mem_init()" function in linux kernel.

      2.Slow down mpu frequency to 266MHZ:

      3.first change SDRAM parameter, i modified sdram_config register some parameter referecence on http://processors.wiki.ti.com/index.php/Setting_up_AM35x_SDRC_registers.

Hardware:

      1.replace all components except  AM3505 CPU  on issue boards,but the issue still exist.

I will continue study Setting_up_AM35x_SDRC_registers to adjust the SDRC registers.

Can anybody give us something suggestion for this issue?

Thanks!

Best Regards!