不使用PC机,只用两个FPGA开发板实现IIC主从数据回环具体代码
时间: 2024-06-12 20:06:46 浏览: 11
由于不知道你使用的FPGA开发板型号,以下代码只是大概的代码框架,需要根据具体开发板型号自行修改。
IIC主机代码:
```
module i2c_master(
input clk,
input rst,
output scl,
inout sda
);
reg [7:0] addr;
reg [7:0] data;
reg [7:0] ack;
reg [7:0] state;
assign scl = state[0];
always @(posedge clk) begin
if (rst) begin
state <= 8'b00000001; // IDLE state
addr <= 8'b00000000;
data <= 8'b00000000;
ack <= 8'b00000000;
end else begin
case (state)
8'b00000001: begin // IDLE state
sda <= 1'b1;
state <= 8'b00000010; // start bit
end
8'b00000010: begin // start bit
sda <= 1'b0;
state <= 8'b00000011; // send address
end
8'b00000011: begin // send address
sda <= addr[7];
addr <= addr << 1;
state <= 8'b00000100; // read ack
end
8'b00000100: begin // read ack
if (sda == 1'b0) begin // got ack
state <= 8'b00000101; // send data
end else begin // no ack
state <= 8'b00001001; // stop bit
end
end
8'b00000101: begin // send data
sda <= data[7];
data <= data << 1;
state <= 8'b00000110; // read ack
end
8'b00000110: begin // read ack
if (sda == 1'b0) begin // got ack
state <= 8'b00000010; // start bit
end else begin // no ack
state <= 8'b00001001; // stop bit
end
end
8'b00001001: begin // stop bit
sda <= 1'b0;
state <= 8'b00000001; // IDLE state
end
endcase
end
end
endmodule
```
IIC从机代码:
```
module i2c_slave(
input clk,
input rst,
input scl,
inout sda
);
reg [7:0] addr;
reg [7:0] data;
reg [7:0] ack;
reg [7:0] state;
assign sda = state[1] ? ack[0] : data[0];
always @(posedge clk) begin
if (rst) begin
state <= 8'b00000001; // IDLE state
addr <= 8'b00000000;
data <= 8'b00000000;
ack <= 8'b00000000;
end else begin
case (state)
8'b00000001: begin // IDLE state
if (scl == 1'b0) begin
state <= 8'b00000010; // start bit
end
end
8'b00000010: begin // start bit
if (scl == 1'b1) begin
state <= 8'b00000011; // receive address
end
end
8'b00000011: begin // receive address
addr <= addr << 1;
addr[0] <= sda;
if (addr == 8'b10101010) begin // address match
ack <= 1'b0;
state <= 8'b00000100; // read/write bit
end
if (addr == 8'b10101011) begin // address match
ack <= 1'b0;
state <= 8'b00000110; // read data
end
if (addr == 8'b10101100) begin // address match
ack <= 1'b0;
state <= 8'b00001000; // write data
end
end
8'b00000100: begin // read/write bit
if (scl == 1'b1) begin
if (sda == 1'b1) begin // read bit
ack <= data[7];
state <= 8'b00000101; // send data
end else begin // write bit
state <= 8'b00000111; // receive data
end
end
end
8'b00000101: begin // send data
if (scl == 1'b1) begin
data <= data << 1;
ack <= 1'b0;
state <= 8'b00000010; // start bit
end
end
8'b00000110: begin // read data
if (scl == 1'b1) begin
data <= data << 1;
data[0] <= sda;
ack <= 1'b0;
state <= 8'b00000010; // start bit
end
end
8'b00000111: begin // receive data
if (scl == 1'b1) begin
data <= data << 1;
data[0] <= sda;
state <= 8'b00001000; // write data
end
end
8'b00001000: begin // write data
if (scl == 1'b1) begin
ack <= 1'b0;
state <= 8'b00001001; // read ack
end
end
8'b00001001: begin // read ack
if (scl == 1'b0) begin
ack[0] <= sda;
state <= 8'b00000010; // start bit
end
end
endcase
end
end
endmodule
```