[U-Boot] [PATCH] Add mpc5125ads board and processor to the mpc512x family
Kenneth Johansson
kenneth at southpole.se
Wed Oct 21 17:20:24 CEST 2009
On Mon, 2009-10-19 at 16:45 -0600, John Rigby wrote:
> Regarding 512x psc register maps:
>
> The register map for 5125 does not just change the size of the registers.
> Some registers change locations. The issue is that the hardware guys
> decided to "fix" the old broken register access. The 5200, 5121, 5123 had
> some registers that were:
>
> Function A when read but function B when written.
I would like to hear what the designer had for argument to justify that
solution. Another favorite is the write only register.
GPIO without set/reset registers that force a read/modify/write cycle.
Then we have things that are more bugs than design
The "god" register that is not affected by any reset turning a
reboot/reset into a game of chance.
The occasional write register.
do {
*reg =xx
}while (*reg != xx)
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