帮我写一个I2C master程序用verilog
时间: 2023-11-23 21:06:32 浏览: 81
好的,以下是一个简单的I2C master程序的Verilog代码:
```
module I2C_Master(
input wire clk,
input wire rst,
input wire sda_i,
output wire sda_o,
output wire scl_o
);
// I2C state machine states
localparam IDLE = 2'b00;
localparam START = 2'b01;
localparam WRITE_ADDR = 2'b10;
localparam WRITE_DATA = 2'b11;
// I2C state machine signals
reg [1:0] state;
reg [7:0] data_out;
reg [2:0] bit_count;
reg sda_dir;
wire sda;
assign sda = sda_dir ? sda_o : sda_i;
always @(posedge clk or negedge rst) begin
if (!rst) begin
state <= IDLE;
scl_o <= 1'b1;
sda_o <= 1'b1;
data_out <= 8'h00;
bit_count <= 3'd0;
sda_dir <= 1'b0;
end else begin
case (state)
IDLE: begin
scl_o <= 1'b1;
sda_o <= 1'b1;
if (!sda_i) begin
state <= START;
end
end
START: begin
scl_o <= 1'b0;
sda_o <= 1'b0;
state <= WRITE_ADDR;
end
WRITE_ADDR, WRITE_DATA: begin
if (bit_count < 8) begin
// send current bit of data_out
sda_o <= data_out[bit_count];
bit_count <= bit_count + 1;
end else if (bit_count == 8) begin
// send ACK bit
sda_dir <= 1'b0;
bit_count <= 3'd0;
state <= WRITE_DATA;
end else if (bit_count == 9) begin
// check ACK bit
sda_dir <= 1'b1;
if (sda_i) begin
// NACK received, stop transaction
state <= IDLE;
end else begin
// ACK received, continue transaction
state <= WRITE_DATA;
end
end
end
endcase
end
end
endmodule
```
这个I2C master程序的基本思路是使用状态机来控制I2C总线上的通信。在I2C总线上发送数据时,程序将数据分为地址和数据两个部分,并在每个部分的传输中使用状态机来控制数据的发送和接收。在程序中,我们使用了一个计数器来跟踪我们正在发送的字节中的当前位。
请注意,这个程序只是一个示例,可能需要根据具体的应用场景进行修改。
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