Level 47: Create Computer

Task

Final level! Write top.v — the top-level module that instantiates the CPU and connects it to the physical ports of the Tang Nano 9K board.

The project contains several files (tabs on the left):

• top.v — editable: your top-level module.
• cpu.v — read-only: Counter8 → ROM → Reg8 (simplified processor).
• counter8.v, adder8.v, full_adder.v, reg8.v — read-only: standard building blocks.

Top interface: clk (clock), top_sw[7:0] (switches), top_led[7:0] (LEDs). Press «Build Computer» — the project assembles into a ZIP archive with pins.cst for flashing to the Tang Nano 9K.

Solution

The Top module is extremely simple — just instantiate the CPU and wire the ports:

module Top(
    input wire clk,
    input wire [7:0] top_sw,
    output wire [7:0] top_led
);
  CPU cpu(clk, top_sw, top_led);
endmodule

Then press «Build Computer». The generated ZIP includes:

• All project files (top.v, cpu.v, counter8.v, adder8.v, full_adder.v, reg8.v)
• pins.cst — physical constraints: port-to-pin mapping for Tang Nano 9K (clk → 45, top switches and LEDs)

The ZIP is ready to be loaded into Gowin IDE for synthesis and flashing to the real board!