Mixed HDL on Fomu¶
Hint
It is strongly suggested to get familiar with Verilog on Fomu and VHDL on Fomu examples before tinkering with these mixed language use cases.
“Hello world!” - Blink a LED¶
The canonical “Hello, world!” of hardware is to blink a LED. The
directory mixedhdl/blink contains a VHDL + Verilog example of a blink
project. This takes the 48 MHz clock and divides it down by a large
number so you get an on/off pattern.
Enter the mixedhdl/blink directory and build the demo by using make:
make FOMU_REV=$FOMU_REV
You can then load blink.dfu onto Fomu by using make load or the same
dfu-util -D command we’ve been using so far. You should see a blinking pattern of
varying color on your Fomu, indicating your bitstream was successfully loaded.
If you take a closer look at the sources in mixedhdl/blink, you will find that
modules/components blink and clkgen are written both in VHDL and Verilog.
The Makefile uses blink.vhd and clkgen.v by default. However, any of the
following cases produce the same result:
blink.vhd+clkgen.vblink.v+clkgen.vhdlblink.vhd+clkgen.vhdlblink.v+clkgen.v
You can modify variables VHDL_SYN_FILES and VERILOG_SYN_FILES in the Makefile
for trying other combinations. For a better understanding, it is suggested to compare
these modules with the single file solutions in Verilog on Fomu and VHDL on Fomu.