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add uart.v

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yunlongLi 2024-11-05 15:39:53 +08:00
parent 2a127785de
commit 21a79e6f3f
2 changed files with 269 additions and 2 deletions
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11
protocol/READ.md
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# TODO test the git config
# second test
Peripheral interface is pushed here to do it.
# 1 UART
# 2 SPI
# 3 I2C

260
protocol/uart.v Normal file
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//==========================================================
//--Author : colonel
//--Date : 11-05
//--Module : uart_send
//--Function: uart is diviede into uart_send,uart_reciver
//==========================================================
module uart_send(
//==========================< 端口 >=========================
input clk,
input rst_n,
input tx_en,
input [8 -1:0] tx_din,
output reg uart_txd
);
//==========================< 参数 >=========================
localparam BAUD_RATE = 9600;
localparam CLK_FREQ = 50000000;
localparam BAUD_PERIOD = CLK_FREQ / BAUD_RATE;
//==========================< 信号 >=========================
reg tx_en_sync0;
reg tx_en_sync1;
//=========================================================
//-- tx_en_sync0/1
//=========================================================
always @(posedge clk or rst_n) begin
if (!rst_n) begin
tx_en_sync0 <= 1'b0;
tx_en_sync1 <= 1'b0;
end else begin
tx_en_sync0 <= tx_en;
tx_en_sync1 <= tx_en_sync0;
end
end
wire start_flag = tx_en_sync0 && !tx_en_sync1; //pos pulse
//==========================< 信号 >=========================
reg [16 -1:0] bps_cnt;
reg [4 -1:0] tx_cnt;
//=========================================================
//-- bps_cnt, tx_cnt:
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
bps_cnt <= 'b0;
end else begin
if (bps_cnt < BAUD_PERIOD -1) begin
bps_cnt <= bps_cnt + 1'b1;
end else begin
bps_cnt <= 'b0;
end
end
end
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
tx_cnt <= 'b0;
end else begin
if (bps_cnt==BAUD_PERIOD-1) begin
tx_cnt <= tx_cnt + 1'b1;
end else if(start_flag)begin
tx_cnt <= 1'b0;
end else begin
tx_cnt <= tx_cnt;
end
end
end
//==========================< 信号 >=========================
reg tx_flag;
reg [8 -1:0] tx_data; //floped for uart_din
//=========================================================
//-- tx_flag,tx_data
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
tx_data <= 'd0;
end else begin
if (start_flag) begin
tx_data <= tx_din;
end else if (tx_cnt==4'd9) begin
tx_data <= 0;
end else begin
tx_data <= tx_data;
end
end
end
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
tx_flag <= 1'b0;
end else begin
if (start_flag) begin
tx_flag <= 1'b1;
end else if(tx_cnt==4'd9 && (bps_cnt==BAUD_PERIOD/2)) begin
tx_flag <= 1'b0;
end else begin
tx_flag <= tx_flag;
end
end
end
//=========================================================
//-- uart_txd
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
uart_txd <= 1'b1;
end else begin
if (tx_flag) begin
case (tx_cnt)
4'd0: uart_txd <= 1'b0;
4'd1: uart_txd <= tx_data[0];
4'd2: uart_txd <= tx_data[1];
4'd3: uart_txd <= tx_data[2];
4'd4: uart_txd <= tx_data[3];
4'd5: uart_txd <= tx_data[4];
4'd6: uart_txd <= tx_data[5];
4'd7: uart_txd <= tx_data[6];
4'd8: uart_txd <= tx_data[7];
4'd9: uart_txd <= 1'b1;
default: uart_txd <= 1'b1;
endcase
end else begin
uart_txd <= 1'b1;
end
end
end
endmodule
//==========================================================
//--Author : colonel
//--Date : 11-05
//--Module : uart_reci
//--Function: uart is diviede into uart_send,uart_reciver
//==========================================================
module uart_reciver (
//==========================< 端口 >=========================
input clk,
input rst_n,
input uart_rxd,
output [8 -1:0] uart_txd,
output rx_done
);
//==========================< 参数 >=========================
localparam BAUD_RATE = 9600;
localparam CLK_FREQ = 50000000;
localparam BAUD_PERIOD = CLK_FREQ / BAUD_RATE;
//==========================< 信号 >=========================
reg uart_rxd_r1;
reg uart_rxd_r2;
//=========================================================
//-- uart_rxd_r1/2
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
uart_rxd_r1 <= 1'b0;
uart_rxd_r2 <= 1'b0;
end else begin
uart_rxd_r1 <= uart_rxd;
uart_rxd_r2 <= uart_rxd_r1;
end
end
wire start_flag_neg = uart_rxd_r2 && !uart_rxd_r1;
//==========================< 信号 >=========================
reg [16 -1:0] bps_cnt;
reg [4 -1:0] rx_cnt;
//=========================================================
//-- bps_cnt, rx_cnt:
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
bps_cnt <= 'b0;
end else begin
if (bps_cnt < BAUD_PERIOD -1) begin
bps_cnt <= bps_cnt + 1'b1;
end else begin
bps_cnt <= 'b0;
end
end
end
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
rx_cnt <= 'b0;
end else begin
if (bps_cnt==BAUD_PERIOD-1) begin
rx_cnt <= rx_cnt + 1'b1;
end else if(start_flag_neg) begin
rx_cnt <= 1'b0;
end else begin
rx_cnt <= rx_cnt;
end
end
end
//==========================< 信号 >=========================
reg rx_flag;
//=========================================================
//-- rx_flag
//=========================================================
always @(posedge clk or rst_n) begin
if (!rst_n) begin
rx_flag <= 1'b0;
end else begin
if (start_flag_neg) begin
rx_flag <= 1'b1;
end else if (rx_cnt==4'd9 && (bps_cnt==BAUD_PERIOD/2)) begin
rx_flag <= 1'b0;
end else begin
rx_flag <= rx_flag;
end
end
end
//==========================< 信号 >=========================
reg [8 -1:0] uart_txd_r;
//=========================================================
//-- uart_txd_r
//=========================================================
always @(posedge clk or negedge rst_n) begin
if (!rst_n) begin
uart_txd_r <= 8'b0;
end else begin
if (rx_flag && bps_cnt==BAUD_PERIOD/2) begin
case (rx_cnt)
4'd1: uart_txd_r[0] <= uart_rxd_r1;
4'd2: uart_txd_r[1] <= uart_rxd_r1;
4'd3: uart_txd_r[2] <= uart_rxd_r1;
4'd4: uart_txd_r[3] <= uart_rxd_r1;
4'd5: uart_txd_r[4] <= uart_rxd_r1;
4'd6: uart_txd_r[5] <= uart_rxd_r1;
4'd7: uart_txd_r[6] <= uart_rxd_r1;
4'd8: uart_txd_r[7] <= uart_rxd_r1;
default: ;
endcase
end else begin
uart_txd_r <= uart_txd_r;
end
end
end
endmodule