完整的iic从机verilog代码实现
时间: 2024-12-06 20:27:33 浏览: 62
IIC (Inter-Integrated Circuit)总线是一种用于连接微控制器和其他器件的串行通信协议。在Verilog HDL中实现完整的I2C从机模块通常涉及以下几个部分:数据线管理、地址解析、发送和接收功能以及状态机控制。
以下是简化的I2C从机Verilog代码示例:
```verilog
module iic_slave (
input wire sda, scl, clk,
input wire rst, irq, write_en, address, data_in, data_out,
output reg [7:0] data_out_reg
);
// 状态机枚举
typedef enum { IDLE, START, ADDRESS_0, ADDRESS_1, DATA, STOP } iic_state_t;
// 状态机变量
localparam SDA_INIT = 'b1;
reg [7:0] data_buffer;
reg iic_state_t state;
// I2C初始化函数
always @(posedge clk or posedge rst) begin
if (rst) begin
state <= IDLE;
data_out_reg <= 8'b00000000;
end else if (state == IDLE && rising_edge(clk)) begin
// 对SDA线进行拉高处理
data_out <= SDA_INIT;
end
end
// 状态转移函数
always @(posedge clk or posedge reset) begin
case(state)
IDLE: begin
if (scl == '0' && address == 7'b1110000) begin
state <= START;
end else if (write_en && address == 7'b0000001) begin
state <= ADDRESS_0;
end
end
// ...其他状态转移条件...
endcase
end
// 数据传输函数
always @(posedge clk and (state == DATA || state == ADDRESS_1)) begin
if (!write_en) begin
// 接收数据
if (address == 7'b0000010) begin
data_buffer <= data_in;
end else if (address == 7'b0000011) begin
// 检查ACK信号并更新data_out
if (scl == '1') begin
data_out <= ~data_in; // 应答信号
end else begin
state <= STOP; // 如果应答失败,停止通信
end
end
else begin
// 发送数据缓冲区的内容
data_out <= data_buffer;
end
end
// 结束条件
always @(posedge clk) begin
if (state == STOP && scl == '0') begin
irq <= 1; // 生成中断请求
state <= IDLE;
end
end
endmodule
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