>
> Hi Bob,
>
> Your first assumption is correct: Any access to CS0 address range will
activate CS1 instead of CS0. Access to CS1 address range works as expected, and
just activates CS1 as well. While the mirror bit is set, CS0 is never
activated.
>
> As far as I can see it, it hardly makes any sense to leave the M bit set on an
LPC23xx.
>
> Regards,
> Rolf
> Rolf,
It's always nice to know what one's design will do. The clarification
is greatly appreciated!
--- In l..., "laserplumb" wrote: >
> Does anyone understand exactly what the LPC-23XX Address Mirror bit
'M', in EMC Control Register (EMCControl) does??
> LPC-23XX User Manual Rev.03, Chapter 5 table 60 says that when 'M' =
1 (after reset) "chip select 1 is mirrored to the chip select 0 memory area".
Does this mean that accesses to CS0 address space activate CS1, and not CS0?
That seems to me to suggest that there would be no CS0 accesses in this mode,
unless CS0 and CS1 activate at the same time, which could be possible. It seems
ambiguous to me. Thanks for sharing! Laser Plumb Bob
>
Hi Bob,
Your first assumption is correct: Any access to CS0 address range will activate
CS1 instead of CS0. Access to CS1 address range works as expected, and just
activates CS1 as well. While the mirror bit is set, CS0 is never activated.
As far as I can see it, it hardly makes any sense to leave the M bit set on an
LPC23xx.
Regards,
Rolf
Reply by bobtransformer●February 23, 20102010-02-23
--- In l..., "laserplumb" wrote: >
> Does anyone understand exactly what the LPC-23XX Address Mirror bit
'M', in EMC Control Register (EMCControl) does??
> LPC-23XX User Manual Rev.03, Chapter 5 table 60 says that when 'M' =
1 (after reset) "chip select 1 is mirrored to the chip select 0 memory area".
Does this mean that accesses to CS0 address space activate CS1, and not CS0?
That seems to me to suggest that there would be no CS0 accesses in this mode,
unless CS0 and CS1 activate at the same time, which could be possible. It seems
ambiguous to me. Thanks for sharing! Laser Plumb Bob
> I see this worded just slightly different. Maybe a newer document ??
It says...
without the words "memory area" which may or may not help you at all.
boB
Reply by laserplumb●February 23, 20102010-02-23
Does anyone understand exactly what the LPC-23XX Address Mirror bit
'M', in EMC Control Register (EMCControl) does??
LPC-23XX User Manual Rev.03, Chapter 5 table 60 says that when 'M' = 1
(after reset) "chip select 1 is mirrored to the chip select 0 memory area".
Does this mean that accesses to CS0 address space activate CS1, and not CS0?
That seems to me to suggest that there would be no CS0 accesses in this mode,
unless CS0 and CS1 activate at the same time, which could be possible. It seems
ambiguous to me. Thanks for sharing! Laser Plumb Bob