Silicon Chip – April 2019

siliconchip.com.au Australia’s electronics magazine April 2019 37

Screen7: we would
never have guessed
these properties, so
we’re glad we found
a guide to help us
out. Make sure you
don’t select NVCM
programming. That
is the non-erasable
(write-once)
memory built into
the iCE40HX-1k IC.
We use the flash
memory instead,
to allow repeated
write/erase cycles.

vhdl” file from the SILICON CHIP web-
site, associated with this article, or
search based on the year and month of
publication. Copy this file to within the
project folder, then add it to the project
by right-clicking on “Add Synthesis
Files”. Select the file and then press
the “>>” button to add it to the project.
The “Run Synplify Pro Synthesis”
button is the first step in turning the
project into a bitstream. Double-click
this, and check that there are no er-
rors. We got an error message about
the license file, but it worked anyway.
Next click “Import P&R Input Files”.
You should see a pattern of working
through several steps along the left-
hand side of the project window, with
the green triangles turning into ticks
as the steps are completed by double-
clicking on them (see Screen5).
After the P&R (place and route) files
have been imported, the pins need to
be assigned. This is done with the Pin
Constraints Editor, selected from the
row of icons below the menus. In our
version, it is the fourth icon, which
looks like a blue square with pins com-
ing out of it.
The physical pin to I/O pin mapping
is shown in Table 1. LED1 and LED2
should be set to pins 95 and 96 (or
any of the other LED pins from the ta-
ble), and “clk” (the clock signal input)
should be set to pin 21. Save the project
to register the new pin assignments.
Finally, in turn, double click “Run
Placer”, “Run Router” and “Generate

Bitmap”. The generated bitmap is the

file that will be loaded onto the iCE-

stick. It can be found buried within

the project folder, eg, \BLINK_Im-

plmnt\sbt\outputs\bitmap\BLINK_

bitmap.bin

Diamond Programmer

Now we use the Diamond Program-

mer application to load the bitstream

onto the iCEstick. Open Diamond Pro-

grammer, select “Create a new blank

project” and click OK.

Under “Cable Settings” to the right,

click “Detect Cable”; the selected ca-

ble should include FTDI in its name.

We found we had to set the port to

FTUSB-1 (see Screen6).

In the main window, set the device

family to iCE40 and the device to iCE-

40HX1K. Under File Name, browse to

the bitmap file created by iCEcube2

and select it.

Click the “Device Properties” icon

(a chip with a small yellow pencil)

and set that as shown in the screen

grab (Screen7). Finally, click the “Pro-

gram” button to transfer the bitstream

to the iCEstick.

If all is well, your Output Window at

bottom left should look like our screen-

shot, and you should see two LEDs

flashing alternately on the iCEstick.

Conclusion

We devoted more space to describing

the iCEcube2 and Diamond Program-

mer software than IceStudio because

it requires more work to achieve the

same result.

We found that IceStudio was a real

pleasure to use and would highly rec-

ommend it to anyone who has not

worked with FPGAs before. We found

a couple of small glitches, including

occasional crashes even on quite small

projects. So save your work often.

We also found IceStudio became

quite sluggish on larger projects, taking

some time to zoom and move around.

We imagine that as we become more

proficient with Verilog, that our IceS-

tudio projects will consist of nothing

more than a single large code block,

which should not present the same

performance issues as lots of smaller

blocks.

IceStudio also appears to have the

benefit of being written specifically

for development boards such as the

iCEstick.

If you are a professional developer,

especially someone looking to build

an FPGA into an end product, the flex-

ibility and complexity of iCEcube2 will

be warranted. Just choosing a different

flash IC to that fitted or another small

hardware change different to the iCEs-

tick would probably be enough to ham-

per IceStudio in these cases.

With iCEcube2, once we had our

project set up, everything worked quite

well; similarly, Diamond Programmer

worked quite well, although the time

spent pulling hair and debugging cryp-

tic error messages was quite a bit more

than we had hoped.

But for someone who has not worked

with FPGAs before, IceStudio will give

a smooth, easy way for you to become

accustomed to what is possible.

In terms of hardware, there are a few

development boards around which

feature more powerful FPGAs than

the iCEstick.

But for now, the iCEstick suits our

purposes, and we think it will be a great

starting point for those wishing to try

out FPGAs for the first time.

The iCEstick is available from Mous-

er and Digikey; both offer free interna-

tional express delivery for orders over

AUD $60.

The iCEstick is around $30-40, so

you could order two and get free deliv-

ery, or order one and something else.

Use the following links:

siliconchip.com.au/link/aao1

or

siliconchip.com.au/link/aao2 SC