vistaでquartus その4

概要

vistaでquartusやってみた。
serial叩いてみた。

環境

windows vista 32bit
quartus ii v13.0
ep2c5t144ボード

写真

サンプルコード

module test1(input clk, input rst, output reg tx = 1);
	reg [7:0] data;
	reg [15:0] cnt_p;
	reg [15:0] cnt_n;
	reg out_p;
	reg out_n;
	reg [4:0] state;
	parameter rate = 5208;
	assign uart_clk = out_p ^ out_n;
	initial
	begin
		cnt_p = 16'd1;
		cnt_n = 16'd1;
		out_p = 0;
		out_n = 0;
		state = 0;
		tx = 1;
		data = 8'h55;
	end
	always @(posedge clk)
	begin
		cnt_p <= cnt_n + 16'd1;
		if (cnt_n == rate)
		begin
			cnt_p <= 16'd1;
			out_p <= ~out_p;
		end
	end
	always @(negedge clk)
	begin
		cnt_n <= cnt_p + 16'd1;
		if (cnt_p == rate)
		begin
			cnt_n <= 16'd1;
			out_n <= ~out_n;
		end
	end
	always @(posedge uart_clk or negedge rst)
	begin
		if (!rst)
		begin
			state <= 0;
			tx <= 1;
		end
		else
		begin
			if (state == 0)
			begin
				state <= 1;
			end
			else if (state != 0)
			begin
				state <= state + 1;
				if (state == 2)
				begin
					tx <= 0;
				end
				else if (state > 2 && state <= 10)
				begin
					tx <= data[state - 3];
				end
				else if (state == 11)
				begin
					state <= 0;
					tx <= 1;
				end
			end
		end
	end
endmodule

以上。