[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [microblaze-uclinux] CFI Flash on 8bit bus?

To: <microblaze-uclinux@xxxxxxxxxxxxxx>
Subject: RE: [microblaze-uclinux] CFI Flash on 8bit bus?
From: "David Banas" <dbanas@xxxxxxxxxxxxxx>
Date: Thu, 7 Jul 2005 13:44:05 -0700
In-reply-to: <42CD8AF2.2020800@lucent.com>
Reply-to: microblaze-uclinux@xxxxxxxxxxxxxx
Sender: owner-microblaze-uclinux@xxxxxxxxxxxxxx
Thread-index: AcWDL/SUN2YlO6XfT6yoYt/vYv/JqgABJ6Pw

Thanks for pursuing this, Michael!

David Banas
Field Applications Engineer
Nu Horizons Electronics Corp.
2070 Ringwood Avenue
San Jose, CA 95131
(408)434-0800 - office
(415)846-5837 - cell
http://www.nuhorizons.com
> -----Original Message-----
> From: owner-microblaze-uclinux@itee.uq.edu.au [mailto:owner-microblaze-
> uclinux@itee.uq.edu.au] On Behalf Of Michael Libeskind
> Sent: Thursday, July 07, 2005 1:05 PM
> To: microblaze-uclinux@itee.uq.edu.au
> Subject: Re: [microblaze-uclinux] CFI Flash on 8bit bus?
>
> So far for me,
> HACK + C_INCLUDE_DATAWIDTH_MATCHING = '1' = stuck flash bit 7
> HACK + C_INCLUDE_DATAWIDTH_MATCHING = '0' = working OK (with the known
> limitation that SW can not do a 32 bit read)
>
> I've been digging through the simulation and with chipscope for most of
> this afternoon and haven't found the problem yet.  I'll keep you posted.
>
>
> David Banas wrote:
> > Greg,
> >
> >
> >
> > Thanks for the correction. What happens if you use the hack and set
> > C_INCLUDE_DATAWIDTH_MATCHING to "0"?
> >
> >
> >
> > David Banas
> > Field Applications Engineer
> > Nu Horizons Electronics Corp.
> > 2070 Ringwood Avenue
> > San Jose, CA 95131
> > (408)434-0800 - office
> > (415)846-5837 - cell
> > http://www.nuhorizons.com
> >
> > ------------------------------------------------------------------------
> >
> > *From:* owner-microblaze-uclinux@itee.uq.edu.au
> > [mailto:owner-microblaze-uclinux@itee.uq.edu.au] *On Behalf Of *Greg
> Miller
> > *Sent:* Thursday, July 07, 2005 12:37 PM
> > *To:* microblaze-uclinux@itee.uq.edu.au
> > *Subject:* RE: [microblaze-uclinux] CFI Flash on 8bit bus?
> >
> >
> >
> > No, you must use the hack and keep DATA_WITCH_MATCHING=1.
> >
> > */David Banas <dbanas@nuhorizons.com>/* wrote:
> >
> > As I understand it,
> >
> > - C_INCLUDE_DATAWIDTH_MATCHING
> > Setting this parameter to "1" for a particular memory bank (any
> > type, FLASH or otherwise) causes the EMC peripheral to "report" its
> external
> > device as a 32-bit unit to the MicroBlaze and conduct as many
> consecutive
> > reads/writes as are necessary, in order to "fill" the internal 32-bit
> data
> > path of the OPB bus, whenever the MicroBlaze issues a read/write from/to
> > that particular peripheral. So, for instance, in the case of an external
> > 16-bit wide FLASH chip, when the EMC receives a request from the
> MicroBlaze,
> > via the OPB bus, to read/write from/to the FLASH, that request comes in
> the
> > form of a 32-bit read/write. The EMC then performs 2 consecutive
> > reads/writes, in order to fulfill the request. In the case of FLASH
> memory,
> > this works fine for reads, but not for writes, due to the writing
> algorithm
> > used by most common FLASH memory chips, which requires that a command to
> > write data be written to the chip immediately before the actual data to
> be
> > stored is written. The assumptions being made by the EMC, when operated
> in
> > "data width matching" mode, break this algorithm. So, you must leave the
> > C_INCLUDE_DATAWIDTH_MATCHING parameter set to "0" for any EMC-controlled
> > memory banks that are FLASH.
> >
> > - EMC Peripheral HDL hack
> > This modification to the HDL code for the EMC peripheral, made by
> > Greg Miller of Avnet-Denver, forces EMC writes to use a "non-data width
> > matching" protocol, regardless of the state of the
> > C_INCLUDE_DATAWIDTH_MATCHING parameter.
> >
> > Now, here's the problem with what I just wrote, above: if both
> paragraphs,
> > above, are correct, then we ought to be able to turn on data width
> matching,
> > reaping its rewards when reading from FLASH without breaking our writes
> to
> > FLASH. However, this doesn't seem to be the c! ase, as you report
> needing to
> > set C_INCLUDE_DATAWIDTH_MATCHING to "0", in order to get things working.
> So,
> > there's something I still don't understand about all this.
> >
> > Greg? John? Class? Anyone? Beuller?
> >
> >
> > David Banas
> > Field Applications Engineer
> > Nu Horizons Electronics Corp.
> > 2070 Ringwood Avenue
> > San Jose, CA 95131
> > (408)434-0800 - office
> > (415)846-5837 - cell
> > http://www.nuhorizons.com
> >>  -----Original Message-----
> >>  From: owner-microblaze-uclinux@itee.uq.edu.au [mailto:owner-
> microblaze-
> >>  uclinux@itee.uq.edu.au] On Behalf Of Michael Libeskind
> >>  Sent: Thursday, July 07, 2005 6:36 AM
> >>  To: microblaze-uclinux@itee.uq.edu.au
> >>  Subject: Re: [microblaze-uclinux] CFI Flash on 8bit bus?
> >>
> >>  Can someone tell me a little bit more about the issues with the EMC
> core
> >>  and C_INCLUDE_DATAWIDTH_MATCHING? I'm actually using u-boot on an
> ML403
> >>  board and have changed the flash to be just 16 bits wide ! because my
> >>  real production board will have just one flash chip.
> >>
> >>  If C_INCLUDE_DATAWIDTH_MATCHING_0 is set to 0 everything works fine
> and
> >>  I can read and write the flash chip as expected 16 bits at a time.
> >>
> >>  If C_INCLUDE_DATAWIDTH_MATCHING_1 is set to 1 I can no longer
> read/write
> >>  as 16 bits. I end up with bit 7 of the flash stuck. Example, In u-boot
> >>  I execute:
> >>
> >>  => mw.w 0x68000000 0x10 (unlock)
> >>  => mw.w 0x68000000 0x1234 (write 0x1234)
> >>  => mw.w 0x68000000 0xff (switch to memory array)
> >>  => md.w 0x68000000 10 (read)
> >>  68000000: 12b4 ffff ffff ffff ffff ffff ffff ffff ................
> >>  68000010: ffff ffff ffff ffff ffff ffff ffff ffff ................
> >>  =>
> >>
> >>  The status right before the read would have been 0x0080 so I think
> that
> >>  may have something to do with the position of the stuck bit. I have
> >>  updated mem_state_machine.vhd and mem_steer.vhd in
> >>  /hw/XilinxProcessorIPLib/pcores/emc_common_v2_00_a/hdl/vhdl with the
> >>  hacked version for 16 bits and everything looks great in simulation. I
> >>  plan on breaking out chipscope later today, but if anyone has any
> >>  insight I would certainly appreciate it.
> >>
> >>  Thanks
> >>
> >>
> >>
> >>  Errol Terblanche wrote:
> >>  > Hi David,
> >>  >
> >>  > Ahh, so that is why it specifically mentions "16-bit flash works
> with
> >>  JFFS2
> >>  > filesystem". :-).
> >>  >
> >>  > Thanks for the info.
> >>  >
> >>  > Thanx,
> >>  > E
> >>  >
> >>  ___________________________
> >>  microblaze-uclinux mailing list
> >>  microblaze-uclinux@itee.uq.edu.au
> >>  Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-
> uclinux
> >>  Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-
> >>  uclinux/
> >>
> >>
> >>
> ________________________________________________________________________
> >>  This email has been scanned for all viruses by the MessageLabs Email
> >>  Security System. For more information on a proactive email security
> >>  service working around the clock, around the globe, visit
> >>  http://www.messagelabs.com
> >>
> ________________________________________________________________________
> >
> >
> > ___________________________
> > microblaze-uclinux mailing list
> > microblaze-uclinux@itee.uq.edu.au
> > Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
> > Mailing List Archive :
> > http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/
> >
> >
> > ________________________________________________________________________
> > This email has been scanned for all viruses by the MessageLabs Email
> > Security System. For more information on a proactive email security
> > service working around the clock, around the globe, visit
> > http://www.messagelabs.com
> > ________________________________________________________________________
> >
>
>
> --
> Michael Libeskind
>   mbl@lucent.com
>    732-949-7657
> ___________________________
> microblaze-uclinux mailing list
> microblaze-uclinux@itee.uq.edu.au
> Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
> Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-
> uclinux/
>
>
> ________________________________________________________________________
> This email has been scanned for all viruses by the MessageLabs Email
> Security System. For more information on a proactive email security
> service working around the clock, around the globe, visit
> http://www.messagelabs.com
> ________________________________________________________________________


___________________________
microblaze-uclinux mailing list
microblaze-uclinux@itee.uq.edu.au
Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/

Follow-Ups:
- [microblaze-uclinux] problems with broadcast packets
  - From: Antti Lukats
- Re: [microblaze-uclinux] CFI Flash on 8bit bus?
  - From: Michael Libeskind

References:
- Re: [microblaze-uclinux] CFI Flash on 8bit bus?
  - From: Michael Libeskind

Prev by Date: RE: [microblaze-uclinux] CFI Flash on 8bit bus?
Next by Date: RE: [microblaze-uclinux] CFI Flash on 8bit bus?
Previous by thread: Re: [microblaze-uclinux] CFI Flash on 8bit bus?
Next by thread: Re: [microblaze-uclinux] CFI Flash on 8bit bus?
Index(es):
- Date
- Thread