[U-Boot-Users] minimum bdi config to read flash on 85xx

[Luiz Neto]

Hi David/Ben/Clemens,

First of all, thanks for helping us!!! You are amazing guys!

Yes, we want to boot from flash. But firstly, we want to validate our
hardware :)

So, let me see if I understood you synchronizing some points:

1- In order to validate my flash circuitry, I don't need LA pins. I'm able
to validate it using just simple FCI commands. Am I right?

I'm not familiar with these command. Probably Robert knows it. But he is out
of the office until tuesday. Can you please give some examples?

2- LA pins are necessary just in case I want to boot from flash. Is it?

3- Our flash is a S29GL01GP MirrorBit. I'm send you our flash schematic and
datasheet. There you can see that WP# is tied high, BYTE# is tied high,
RESET# is high (a FPGA controls this pin) and that there is no address pin
floating.

Thanks in advance!
Luiz


2007/9/6, David Hawkins <dwh at ovro.caltech.edu>:
>
> Hi Luiz,
>
> > This is Luiz and I'm working with Robert in this  project.
>
> Glad to hear he's got someone to grow grey hairs
> with ... if it hasn't fallen out yet.
>
> > Actually, I'm a hardware guy.
>
> So am I ... this week :)
>
> > I read your messages and it seems you're right. However,
> > before introducing these changes on the board, we decided
> > to verify all flash circuitry and we noticed the following:
> >
> > CE# is OK!
> > WE# is OK!
> > OE# is OK!
> >
> > We verified it using a scope and triggering CE# pin. After that, we
> > tried to write to flash through BDI2000 using "mm" command. Again with a
> > scope we checked each address line and apparently everything is fine
> > with the address.
>
> I think that after the processor boots LAD[0:31] activate
> for each address access, its only during boot that LAD[27:31]
> do not toggle, and you have to use LA[27:31]. So its
> that confirmation of the address toggles in this case just
> confirms that the LAD[27:31] bits toggle.
>
> On the bright-side, it sounds like you have the bit
> ordering correct ([27:30])... just not the right bits
> (LAD vs LA).
>
> > We also checked the data being written, and it's ok
> > too. After that, in order to validate the written, we read the same
> > address we had just written. But we got a different value. Therefore we
> > are not writing correctly to flash.
>
> Have you tried using simple CFI flash commands;
> read the manufacturer ID, read the device ID,
> read the sector protection? Don't bother with
> BDI Flash commands just yet, just use memory
> read/write commands.
>
> > Ok, after all, we fixed our board following your tips.
> > We connected LA[27:30] to A[3:0] and A[4:25] to LBA[26:5].
> > But we got the same bad result. I mean we read a wrong data.
> >
> > After, we changed flash access time, decreasing it. And the
> > problem persisted. We changed flash chip and nothing happened.
> >
> > Actually I'm afraid because I can't see what else we can verify
> > on hardware.
> >
> > My opinion is we have mistakes on configuration file. I'm not sure if we
> > are configuring all registers correctly.
> >
> > Do you think it would be helpful if I send you our flash schematic and
> > our configuration file?
>
> Sure, no guarantees, you can send me a copy, or send
> a link to the group. I'm not too knowledgeable on BDI
> config files yet, as I don't have my custom hardware.
> However, I have looked at a few hardware designs, so
> perhaps I'll spot something on the schematic. The
> peripherals seem to be pretty similar between the
> PowerQUICCs, so I'll dig up a working configuration
> file, and look at the difference in register settings.
>
> What is your Flash? Eg. if its say a Spansion device,
> do you have WP# tied high, BYTE# tied low/high, etc?
> Are there any address pins left floating?
>
> Do you have a logic analyzer available? If you did,
> you'd be able to look at the flash controls and write-data
> and convince yourself that your Flash programming
> sequence was correct.
>
> The best advice at the moment, is to access your Flash
> configuration using manual read/write sequences.
>
> Cheers,
> Dave
>
>
>
>
>
>
>
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