[MinnowBoard] Minnowboard MAX with Dediprog em100 pro SPI emulator

[Simon Glass]

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.

Thanks for the pointers.

Regards,
Simon