On Mon, Oct 20, 2003 at 01:16:17AM +0200, Wolfgang Denk wrote:
hello,
in message 20031018002619.GB325@zumanetworks.com you wrote:
two minor things on the 859/866
- measure_gclk() is very inaccurate. Better to use the plprcr and
CFG_8XX_XIN (which MUST BE 10MHz for that cpu) to derive the "real" bus clock.
What do you mean by "very inaccurate" - the intention of the function (as documented) is to measure the "Approx. GCLK frequency in Hz". How bad is "very inaccurate" in your case?
2-3%
the error of using plprcr + XIN is 0%, and given we know XIN is 10MHz for the 859/866 we are using that now.
- the 859/866 does NOT support external speeds higher than 66MHz,
so if cpu_clk is greater, EBDF01 MUST BE USED IN CFG_SCCR
I think this is the case for ALL MPC8xx processors so far. I have never seen one which would allow a bus clock > 66 MHz.
I have a patch for 1, but i no longer have my 859/866 eval board
Maybe you can share it anyway.
i'll put something together this week, time permitting.
it will be ugly, but you can see what we tried to do.
I have no patch for 2, but eventually we should come up with some sort of solution; the 859/866 is almost always configured to run faster than 66MHz.
I don't see why a patch should be needed here. This is a simple matter of getting your board config file right, isn't it?
yes, but somebody really should add a note to the readme :)
time permitting i will try to.
-nye