23. Open-Drain I2C SDA line

How do you plan to solve it?

/*Write your code here*/
module i2c_line(
    input drive_low,
    output tri1 sda         // tri1 = weak pull-up when undriven
);

assign sda = drive_low ? 1'b0 : 1'bz;   // either pull low or release (z)

endmodule