POC that NAND gates achieve functional completeness and can be used to build any complex binary function. In this example, a circuit that computes an 8-bit integer division is built from 1720 NAND gates.

You need to install ghdl to compile and simulate your circuits, and gtkwave to view the evolution of the signals over time.

On Ubuntu, you only need to install the appropriate packages:

sudo apt-get install ghdl gtkwave

bash compile.sh

This will compile the vhdl sources and run bench tests (like regression tests). You can then visualize the results with gtkwave. For example:

gtkwave div8_tb.vcd

In this example, a = 51 (0x33) is divided by b = 4. The calculation finishes after 72 ns (352 ns in the worst case), and the resulting quotient is q = 12 (0x0C), with a remainder of r = 3.