vhdl实现uart程序，分为tx和rx，其中tx输入端口包括Go,Data(7 downto 0)，clk，Tick_bit和rst

以下是一个简单的 VHDL 代码实现 UART 的 TX 模块，其中包括 Go、Data、clk、Tick_bit 和 rst 等输入端口：

library ieee;
use ieee.std_logic_1164.all;

entity uart_tx is
    port(
        Go          : in  std_logic;
        Data        : in  std_logic_vector(7 downto 0);
        clk         : in  std_logic;
        Tick_bit    : out std_logic;
        rst         : in  std_logic
    );
end entity;

architecture rtl of uart_tx is
    signal Count         : integer range 0 to 11 := 0;
    signal Bit_Serial    : std_logic_vector(10 downto 0);
    signal Tx            : std_logic := '1';
    signal Tx_Shift_Reg  : std_logic_vector(10 downto 0);
begin
    Tick_bit <= Tx;

    process(clk, rst)
    begin
        if (rst = '1') then
            Count <= 0;
            Bit_Serial <= (others => '0');
            Tx <= '1';
            Tx_Shift_Reg <= (others => '1');

        elsif (rising_edge(clk)) then
            if (Go = '1') then
                case Count is
                    when 0 =>
                        Bit_Serial <= std_logic_vector('1' & Data & '0');
                        Count <= Count + 1;
                    when 1 to 10 =>
                        Bit_Serial <= Bit_Serial(Bit_Serial'high-1 downto 0) & '0';
                        Count <= Count + 1;
                    when 11 =>
                        Tx_Shift_Reg <= Bit_Serial;
                        Tx <= Tx_Shift_Reg(0);
                        Count <= 0;
                end case;
            end if;
        end if;
    end process;
end architecture;

对于 UART 的 RX 模块，类似的代码实现也可以通过类似的方式完成。