make a uart Verilog HDL program

As an AI language model, I cannot write Verilog HDL code, but I can provide a basic structure of a UART program in Verilog HDL.

In Verilog HDL, a UART module can be designed using the following basic structure:

1. Define the module and its input/output ports

module UART (
    input clk,
    input rst,
    input txen,
    input [7:0] txdata,
    output reg tx,
    output reg busy
);

2. Define the internal variables

reg [3:0] state;
reg [7:0] txbuf;
reg bitstart, bitstop;
reg [2:0] bitcnt;

3. Define the state machine for transmitting data

always @ (posedge clk, posedge rst) begin
    if (rst) begin
        state <= 0;
        tx <= 1;
        busy <= 0;
        txbuf <= 0;
        bitcnt <= 0;
        bitstart <= 0;
        bitstop <= 1;
    end else begin
        case (state)
            0: begin // Wait for data to be ready
                if (txen) begin
                    txbuf <= txdata;
                    state <= 1;
                end
            end
            1: begin // Send start bit
                tx <= 0;
                bitstart <= 1;
                bitcnt <= 0;
                state <= 2;
            end
            2: begin // Send data bits
                tx <= txbuf[bitcnt];
                bitcnt <= bitcnt + 1;
                if (bitcnt == 8) begin
                    state <= 3;
                end
            end
            3: begin // Send stop bit
                tx <= 1;
                bitstop <= 0;
                state <= 4;
            end
            4: begin // Wait for stop bit to finish
                if (bitstop) begin
                    state <= 0;
                    busy <= 1;
                end
            end
            default: begin
                state <= 0;
                tx <= 1;
                busy <= 0;
                txbuf <= 0;
                bitcnt <= 0;
                bitstart <= 0;
                bitstop <= 1;
            end
        endcase
    end
end

4. Define the initial values for the internal variables

initial begin
    state <= 0;
    tx <= 1;
    busy <= 0;
    txbuf <= 0;
    bitcnt <= 0;
    bitstart <= 0;
    bitstop <= 1;
end

This is a basic structure for a UART program in Verilog HDL. The actual implementation may vary depending on the specific requirements and design constraints.