Strataflash mapping problem

[Jonathan Larmour]

Enric Bel Prim wrote:
> Hi, again.
> Yes, I agree with Jeffrey Daly that CYGNUM_FLASH_DEVICES should be the real 
> number of flash devices (4 in my platform), and CYGNUM_FLASH_WIDTH should 
> be the number of bits in each device (16 in my platform).  But 
> CYGNUM_FLASH_INTERLEAVE should be 1 for my platform (16 bits devices 
> located in a 16 bit expansion bus of IXP425) and never equal to 
> CYGNUM_FLASH_DEVICES  (as is defined in line 95 in strata.h)....
> Finally I'm considering using the generic driver for the Intel 28fXXX 
> devices instead of the Intel strata to acces the Intel Strata Flash devices 
> of my platform.
> 
> The 28fXXX driver requires the following settings:
> 
> // Platform code must define the below
> // #define CYGNUM_FLASH_INTERLEAVE      : Number of interleaved devices (in 
> parallel)
> // #define CYGNUM_FLASH_SERIES          : Number of devices in series
> // #define CYGNUM_FLASH_WIDTH           : Width of devices on platform
> // #define CYGNUM_FLASH_BASE            : Address of first device
> 
> For my platform I will set:  (CYGNUM_FLASH_INTERLEAVE = 1, 
> CYGNUM_FLASH_SERIES = 4, CYGNUM_FLASH_WIDTH = 16, CYGNUM_FLASH_BASE = 
> 0x50000000)
> I think CYGNUM_FLASH_SERIES  will solve my flash mapping problems???  I 
> wonder why the strata flash driver doesn't allow this setting!!.

Because no-one has implemented it :-).

> Does anybody know  if I can use the 28fXXX driver to acces Intel Strata 
> Flash devices? I mean, will I loose some functionality/feature of the 
> Strata devices if I use the generic 28fXXX driver?

I don't know, but if you look at where CYGNUM_FLASH_SERIES is mentioned in 
the 28fxxx driver, you'll see it should be pretty easy to bring the same 
ideas over into the strata driver if you needed to.

Given the buffered write support is broken, I don't perceive any real 
difference in functionality between the drivers, but I haven't looked in 
detail.

Jifl
-- 
eCosCentric    http://www.eCosCentric.com/    The eCos and RedBoot experts
Visit us at Embedded World 2004, Nürnberg, Germany, 17-19 Feb, Stand 12-449
--["No sense being pessimistic, it wouldn't work anyway"]-- Opinions==mine