[U-Boot-Users] flash interconnection

Wolfgang Denk wd at denx.de
Sat Apr 29 01:01:35 CEST 2006

In message <9c1c9eb80604281305k680939d4j3dd957d0cf0b7530 at mail.gmail.com> you wrote:
> I'm observing electric diagram of Freescale board PQ27e-ADS (MPC8272) about
> the interconnection between cpu MPC 8272 and flash memory. The data bus is
> linked inverted, i.e., flash DQ0 is connected to processor DQ7, flash DQ7 is
> connected to processor DQ0. For the other bytes it is the same (flash DQ8 is
> connected to processor DQ15 and so on).

No, the busses are NOT inverted, they are connected correctly, i. e.
LSB with LSB and MSB with MSB.

Please check in the User's Manual how PowerPC systems number the  bit
(bit 0 = MSB).

> My question: Is it possible to connect the flash memory to the processor in
> a different way (such as flash DQ0 to processor DQ15, flash DQ1 to proc.
> DQ14, ..., flash DQ15 to proc. DQ0)? Is there a pin or register to configure

This is possible. But why would you want to do that? You can  do  all
kinds  of  funny  things. But don't expect that all funny things will
work, though.

> ------=_Part_3450_12788847.1146254730959
> Content-Type: text/html; charset=ISO-8859-1
> Content-Transfer-Encoding: quoted-printable
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And please don't post HTML on this list.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
In any group of employed individuals the only naturally  early  riser
is  _always_  the office manager, who will _always_ leave reproachful
little notes ... on the desks of their subordinates.
                                - Terry Pratchett, _Lords and Ladies_

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