Yes, that is what we did and it worked, including running linux, as I recall.
We have not run extensively with the 66MHz bus clock. Our processor was 166/133/66 rev A.1 so we clocked the processor at 166MHz (MODCK_H = 0101, MODCK[1-3] = 110). We played with overclocking the CPU: we were able to run quite a bit faster than 166MHz at the 33MHz bus speed (300MHz?), but died right away when we tried to overclock with the 66MHz bus speed. For more details, I would have to dig out some notes. gvb At 12:47 PM 12/8/00 -0600, Brian Ford wrote: >Is there any magic in getting the EST8260 board to work with a 66 Mhz bus >clock? I haven't had good luck with a Linux or vxWorks image. > >My board has a 200/166/66 rev A.1 chip. > >I boot using a vxWorks bootrom. I have made a few corrections to the >bootrom so the decrementer frequency is set correctly from the user >dip switches in addition to setting the core, cpm, and bus speeds. > >The scenerio is as follows: > >1.) Burn configuration word to change MODCK_H from 0x0001 to 0x0101 >2.) Swap oscillators 33.0 -> 66.0 Mhz >3.) Set MODCK[1-3] switches to 0x111 (200/133/66) >4.) Mirror 3.) on user switches for vxWorks bootrom to read >5.) Hack head_8260.S to put immr in place for Linux >6.) Set linux board info in embed_config.c to 200/133/66/66 >(core,cpm,bus,brg) making sure there is real space allocated for it >instead or whatever was in r3 when vxWorks booted us. >6.) Reboot. > >vxWorks bootrom runs fine and downloads Linux or vxWorks. > >Linux pannics just before giving me a shell prompt somewhere in tty init. > >vxWorks appears to come up fine, but the muxDevBind fails for the Fast >Ethernet and thus no network communications. Even though the bootrom >just downloaded us successfully over the same interface. > >Has anyone had any luck with the 66 Mhz bus clock? > >-- >Brian Ford >Software Engineer >Vital Visual Simulation Systems >FlightSafety International >Phone: 314-551-8460 >Fax: 314-551-8444 > > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
