[MinnowBoard] Minnowboard MAX with Dediprog em100 pro SPI emulator

[Krause Martin]

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.

Best Regards,
Martin