wishbone_pkg.vhd

        when "1001" => result(i+1) := '9';
        when "1010" => result(i+1) := 'a';
        when "1011" => result(i+1) := 'b';
        when "1100" => result(i+1) := 'c';
        when "1101" => result(i+1) := 'd';
        when "1110" => result(i+1) := 'e';
        when "1111" => result(i+1) := 'f';
        when others => result(i+1) := 'X';
      end case;
    end loop;
    
    -- trim leading 0s
    strip : for i in result'length downto 1 loop
      cut := i;
      exit strip when result(i) /= '0';
    end loop;
    
    return "0x" & result(cut downto 1);
  end f_bits2string;
  
end wishbone_pkg;