[U-Boot-Users] Re: about flash_port_width
Wolfgang Denk
wd at denx.de
Mon Mar 3 09:07:44 CET 2003
Hello,
in message <OE46FvpV02m6DKdu3cg000034a7 at hotmail.com> you wrote:
>
> I read the example "board/lwmon/flash.c" for a configuration of a
> 32 bit wide flash bank using 28F640J3A chips.
...
> But I find a another example for 28F640J3A chips "/board/nx823/flash.c",I
> think there is one flash chips .Something like this:
> #define FLASH_PORT_WIDTH ulong
> #define FLASH_PORT_WIDTHV vu_long
> #define FPW FLASH_PORT_WIDTH
> #define FPWV FLASH_PORT_WIDTHV
>
> " case (FPW)INTEL_ID_28F640J3A:
> info->flash_id += FLASH_28F640J3A;
> info->sector_count = 64;
> info->size = 0x00800000;
> break; /* => 8 MB */ "
>
> static int write_data (flash_info_t *info, ulong dest, FPW data)
> {
> ..............................................
> *addr = (FPW)0x00400040; /* write setup */
> *addr = data;
> ...............................................
> return (0);
> }
>
> Since there is one chip,I think it must perform 16bit data operations.But
> the variable "data" type is ulong(I think it is 32bits),it seems that it
> still performs 32bit operation.Why???
I think this board uses 2 chips in 16 bit configuration, too. The
setting of "info->size" is probably wrong. I cannot check, since I
don't know the hardware.
The MAINTAINERS file lists the NX823 board as orphaned, which means
that nobody actively maintains this port - it may be buggy. There are
several poor ports in the code, but I can only fix those where I have
access to the documentation and to the hardware and probably someone
who pays for the time.
I know that the LWMON configuration is working fine, so you better
use this one as a model ;-)
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
It's a small world, but I wouldn't want to paint it.
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