[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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