[U-Boot] MPC850: strange problem with icache

[Wolfgang Denk]

Dear Guowen SHAN,

In message <cf7369060903290628p2768907p9a0c2e40c898601b at mail.gmail.com> you wrote:
>
> I'm porting u-boot-1.3.1 to customer board, which includes MPC850 and 32MB SDRAM.
> When I turned off icache, bus can work correctly under 25MHz/50MHz clock frequence.
> Note that CPU is working under 50MHz. However, the board only can work with bus
> frequence of 25MHz with enabled icache. If I tried to set bus frequence to 50MHz with
> enabled icache, it will crash with MCE.

Easy problem - actually FAQ: please see
http://www.denx.de/wiki/view/DULG/UBootCrashAfterRelocation

> I don't know why. Since it can work at 25MHz with enabled icache, the UPM words seem
> ok. Thanks for your advices!

Keep in mind that the UPM setup is only part of the required RAM
initialization sequence. Follow the instructions in the chip
manufacturer's manual to the letter.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The number you have dialed is imaginary. Please divide by 0  and  try
again.