verilog iic
时间: 2023-09-11 14:08:07 浏览: 53
Verilog I2C (Inter-Integrated Circuit) is a protocol used to communicate between devices in a synchronous serial communication system. It is used for low-speed peripherals with a data rate of up to 400 kbps. Here is an example code for implementing Verilog I2C:
```
module i2c_master(
input clk,
input reset,
input start,
input stop,
input [7:0] data_in,
output [7:0] data_out,
output reg sda,
output reg scl,
input sda_ack,
input scl_ack
);
reg [7:0] data_out_reg;
reg [7:0] data_out_next;
reg [7:0] data_in_reg;
reg [7:0] data_in_next;
parameter IDLE = 2'b00;
parameter START = 2'b01;
parameter ADDRESS = 2'b10;
parameter DATA = 2'b11;
reg [1:0] state_reg;
reg [1:0] state_next;
assign data_out = data_out_reg;
assign sda_ack = (sda == data_in_reg) ? 1'b1 : 1'b0;
assign scl_ack = 1'b1;
always @(posedge clk, posedge reset) begin
if (reset) begin
sda <= 1'b1;
scl <= 1'b1;
state_reg <= IDLE;
data_out_reg <= 8'h00;
data_in_reg <= 8'h00;
end else begin
sda <= (state_reg == ADDRESS || state_reg == DATA) ? data_out_reg[7] : 1'b1;
case (state_reg)
IDLE: begin
if (start) begin
state_next = START;
end else begin
state_next = IDLE;
end
end
START: begin
scl_next = 1'b0;
sda_next = 1'b0;
state_next = ADDRESS;
end
ADDRESS: begin
if (sda_ack) begin
if (data_out_reg[7:1] == 7'h50 && data_out_reg[0] == 1'b0) begin
sda_next = 1'b1;
state_next = DATA;
end else begin
sda_next = 1'b1;
state_next = IDLE;
end
end else begin
sda_next = data_out_reg[7];
state_next = ADDRESS;
end
end
DATA: begin
if (sda_ack) begin
if (data_out_reg[7:1] == 7'h50 && data_out_reg[0] == 1'b0) begin
sda_next = 1'b1;
state_next = DATA;
end else begin
sda_next = 1'b1;
state_next = IDLE;
end
end else begin
sda_next = data_out_reg[7];
data_out_next = {data_out_reg[6:0], 1'b0};
state_next = DATA;
end
end
endcase
end
end
always @(posedge clk) begin
sda <= sda_next;
scl <= scl_next;
data_out_reg <= data_out_next;
data_in_reg <= {data_in_reg[6:0], sda};
state_reg <= state_next;
end
endmodule
```
This is just an example code and may not work for all applications. It's important to understand the I2C protocol and modify the code accordingly.