Hi,
maybe this question not greatly related with u-boot.
when I read the wiki of u-boot: http://www.denx.de/wiki/view/DULG/UBootCrashAfterRelocation
I noticed this: Standard memory tests are not effective in identifying this type of problem because they do not cause stressful cache burst read/write operations.
We have a board, the ram works fine before, but recently, we need to change the ram for the lack of the original chip. After I read the datasheet of original chip, I found the parameter tRCD is wrong! In code, tRCD is set to 10ns, but in datasheet, the minimal tRCD is 15ns.
I know in u-boot, there is a command name mtest, it is a simple RAM test. it test fine in two tRCD condition. I also try memtester 10 loops, also fine!
Could somebody give me some advice to determine which value of tRCD is better? thanks.
here is the memtester log:
[root@root]# ./memtester 31M 10 memtester version 4.1.2 (32-bit) Copyright (C) 2009 Charles Cazabon. Licensed under the GNU General Public License version 2 (only).
pagesize is 4096 pagesizemask is 0xfffff000 want 31MB (32505856 bytes) got 31MB (32505856 bytes), trying mlock ...locked. Loop 1---10: Stuck Address : ok Random Value : ok Compare XOR : ok Compare SUB : ok Compare MUL : ok Compare DIV : ok Compare OR : ok Compare AND : ok Sequential Increment: ok Solid Bits : ok Block Sequential : ok Checkerboard : ok Bit Spread : ok Bit Flip : ok Walking Ones : ok Walking Zeroes : ok