"tullio.grassi" ...
> I am trying to understand if there is any side-effect of pin-swapping.
> As an example, I was thinking to pin swap data lines of a Flash
> memory; but
> I realized that these devices have special commands sent on the data
> bus, so commands would get screwed-up (and myself too :)

Nope, not the data bus but the address bus - DO NO swap those lines...

Regards,
Arie de Muynck

larwe <zwsdotcom@gmail.com> wrote:
> 
> 
> On Jan 30, 9:47 am, Ico <use...@zeev.nl> wrote:
> 
>> > The datasheet's advice is good. Swap within bytelanes as you wish. Do
>> > not swap between bytelanes.
> 
>>Why not ?
> 
> Because you lose the ability to address individual bytelanes uniquely 
> if you mix them up like this.

Of course, I'm sorry, for some reason I misread your previous answer, I
thought you ment to swapy *between* bytelanes, not *within*. My wrong.
 

-- 
:wq
^X^Cy^K^X^C^C^C^C

On Jan 30, 9:47 am, Ico <use...@zeev.nl> wrote:

> > The datasheet's advice is good. Swap within bytelanes as you wish. Do
> > not swap between bytelanes.

>Why not ?

Because you lose the ability to address individual bytelanes uniquely 
if you mix them up like this.

On Jan 30, 9:32 am, "tullio.grassi" <tullio.gra...@gmail.com> wrote:
> I am trying to understand if there is any side-effect of pin-swapping.
> As an example, I was thinking to pin swap data lines of a Flash
> memory; but I realized that these devices have special commands
> sent on the data bus, so commands would
> get screwed-up (and myself too :)

Well, yes - but this is easily handled with macros in your program. 
This sort of thing is very common.

larwe <zwsdotcom@gmail.com> wrote:
> 
> 
> On Jan 30, 8:59 am, "tullio.grassi" <tullio.gra...@gmail.com> wrote:
> 
>> I'd like to be 100% sure that the swapping will not create problems
>> once the PCB is built.
> 
> The datasheet's advice is good. Swap within bytelanes as you wish. Do 
> not swap between bytelanes. 

Why not ?

-- 
:wq
^X^Cy^K^X^C^C^C^C

larwe ha scritto:

> On Jan 30, 8:59 am, "tullio.grassi" <tullio.gra...@gmail.com> wrote:
>
> > I'd like to be 100% sure that the swapping will not create problems
> > once the PCB is built.
>
> The datasheet's advice is good. Swap within bytelanes as you wish. Do
> not swap between bytelanes. What further information do you need?

I am trying to understand if there is any side-effect of pin-swapping.
As an example, I was thinking to pin swap data lines of a Flash 
memory; but
I realized that these devices have special commands sent on the data 
bus, so commands would
get screwed-up (and myself too :)

On Jan 30, 8:59 am, "tullio.grassi" <tullio.gra...@gmail.com> wrote:

> I'd like to be 100% sure that the swapping will not create problems
> once the PCB is built.

The datasheet's advice is good. Swap within bytelanes as you wish. Do 
not swap between bytelanes. What further information do you need?

Hi,

 to ease the routing of my PCB, I'd like to swap some data lines on a 
SDRAM.
I'd like to be 100% sure that the swapping will not create problems 
once the PCB is built.
I use a SDRAM MT48LC8M16A2 from Micron.
The only documentation that I found is:
http://www.freescale.com/files/32bit/doc/app_note/AN2582.pdf
about DDR, and they say
"Pin-swap within a given byte lane to optimize the data bus routes 
further. Caution:
Do not swap individual data bits across different byte lanes."

Is there any other recommendation ?
Any positive experience ?

Thanks