[MinnowBoard] Minnowboard MAX with Dediprog em100 pro SPI emulator

[Krause Martin]

Hi Simon,

> -----Ursprüngliche Nachricht-----
> Von: elinux-MinnowBoard [mailto:elinux-minnowboard-
> bounces at lists.elinux.org] Im Auftrag von Simon Glass
> Gesendet: Sonntag, 18. Januar 2015 22:12
> An: MinnowBoard Development and Community Discussion
> Betreff: Re: [MinnowBoard] Minnowboard MAX with Dediprog em100 pro
> SPI emulator
> 
> Hi Martin,
> 
> On 9 January 2015 at 00:06, Krause Martin <Martin.Krause at tq-group.com>
> wrote:
> > Hi,
> >
> >> On 7 January 2015 at 01:14, Krause Martin
> >> <Martin.Krause at tq-group.com>
> >> wrote:
> >> > Hi Simon,
> >> >
> >> > I'm using both - the SF100 programmer and the EM100Pro emulator -
> >> > on the Minnowboard Max with success.
> >> >
> >> > You could adapt the EM100Pro without soldering with the EM-TC-8
> >> > SO8 Test Clip:
> >> > http://www.dediprog.com/pd/programmer-accessories/EM-TC-8
> >> > This clip is directly plugged "over" the SPI flash chip. With
> >> > around
> >> > 50 USD it is not really cheap, but you could save a lot of time
> >> > during development if you have to update the BIOS a lot compared to
> >> > the SF100
> >> programmer.
> >> >
> >> > One erase-program cycle with the SF100 programmer needs around 85 s
> >> > on my board (55 s for erase and 30 s for program). Compared to this
> >> > it only takes 4-5 s to update the BIOS image in the EM100 emulator.
> >> >
> >>
> >> In my case I'm only updating around 512KB each time so it should be
> faster.
> >> But still the EM100 is better.
> >
> > Since I've not mentioned it. My time measurement was to erase and
> > program the whole Chip, which is 8 MiB.
> >
> >> > On the EM100Pro I configured the following to use it with the
> >> > Minnowboard Max:
> >> >
> >> >   Memory Type: W25Q64DW, Manufacturer: Winbond, Size: 8192 (KB)
> >> >   Hold Pin Status While Emulation: Default Low
> >>
> >> I'm not sure I have the hold pin status option - I'm using the 'em100'
> >> Linux utility. Maybe I have an old version.
> >
> > I only know the windows utility, but since the EM100 is an emulator, I
> > would assume, that it is the default to drive the hold pin low also
> > with the Linux utility, to deactivate  all other devices which are
> > connected to the SPI bus to not interfere with the emulator.
> >
> > On the Minnow Max board the hold pin is connected to VCC 1V8 over a
> > 10k pull up, so you could pull this pin fix to ground without harm,
> > for example if you connect the hold pin of the EM-TC-8 clip to ground.
> > This should work without an soldering iron, but I do not think that
> > this is necessary at all with the linux utility.
> >
> >> > And please note, that the EM100Pro does not support a SPI-Clock of
> >> > 50 MHz. I configured all SPI-Clocks (Read, Write and Fast Read) in
> >> > the Component Section of the BIOS Flash Descriptor to 20 MHz, when
> >> > I use the EM100PRO (you could do this with the intel FITC tool when
> >> > you combine the UEFI BIOS with the TXE firmware). If you use the
> >> > prebuild Minnowboard Max images you do not need to worry about the
> >> > SPI clock speed, because there the default seems already to be
> >> > 20 MHz.
> >> >
> >>
> >> Thanks very much for this info. I didn't realise that those clips
> >> could overwrite the SPI flash chip. Maybe I don't need to break out
> >> the soldering iron after all.
> >
> > If the hold pin of the SPI flash chip is pulled low, then the whole
> > Chip goes into tri-state, thus behaves as if not placed. So the
> > emulator which is connected over the EM-TC-8 clip replaces the flash chip.
> >
> > Please note that, the EM100 is no flash programmer, so it could not
> > change the content of the onboard flash. It only emulates the flash
> > for the time it is connected. If the emulator is unplugged, the system
> > boots from the onboard flash again, with the original content of the
> > flash.
> 
> I got one of these clips and it seems to work well.
> 
> Unfortunately the em100 utility that I have for Linux does not work - the
> board does not boot. I found an old Windows XP laptop and managed to get
> cygwin on it, so now I can scp the file each time and write it to the em100
> with the cmdline tool. Horrible, but I can put up with it until I figure out the
> problem. I suppose I could ssh to the windows machine and therefore do it
> as part of my build flow.
[Krause Martin] 

Thanks for the info! I unfortunately haven't used em100 under linux yet,
so I don't have any tips for it. 

Within the windows tool there is a trace feature integrated, which logs all
SPI communication on the bus between the flash and the emulator. Maybe 
you could figure out the not-booting-with-the-linux-utility problem by 
analyzing the SPI traffic - if the linux utility does alos have the trace feature.
It helped me to figure out the fact, that the em100 does not support a 
50 MHz clock, at least.

Best regards,
Martin