On Jan 31, 2007, at 7:45 AM, Klaus Klein wrote:

> Frank Wille wrote:
>
>> - Why is battable an array with 512 entries? 16 should be enough.
>
> That's because the MPC601 can translate only up to 8M per BAT, as  
> opposed other, less limited OEA implementations, an thus needs that  
> many entries.  (You can check dsi601trap; it differs, among other  
> details, in the amount of fault address -> battable entry# shifting.)

I've been thinking that using 8M for the normal OEA would be a good  
idea as well.  You could still use a 256M/128M/64M/32M/16M as well as  
8M, you'd just fill in 32/16/8/4/2 entries with the large entry but  
it would allows finer resolution of the BATs.