【iCore4 双核心板_FPGA】例程十四：基于I2C的ARM与FPGA通信实验

实验现象：

1、先烧写ARM程序，然后烧写FPGA程序。

2、打开串口精灵，通过串口精灵给ARM发送数据从而给FPGA发送数据 ，会接收到字符GINGKO。

3、通过串口精灵发送命令可以控制ARM·LED和FPGA·LED。

命令格式
LEDR\CR\LF ARM·LED、FPGA·LED亮
LEDG\CR\LF ARM·LED、FPGA·LED亮
LEDB\CR\LF ARM·LED、FPGA·LED亮

核心代码：

int main(void)
{

  /* USER CODE BEGIN 1 */
    int i;
    char buffer[];
    char i2c_buffer[];
  /* USER CODE END 1 */

  /* MCU Configuration----------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART6_UART_Init();

  /* USER CODE BEGIN 2 */
    i2c.initialize();
    usart6.initialize();
    usart6.printf("Hello,I am iCore4!\r\n");
    LED_GREEN_ON;

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while ()
  {
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
        if(usart6.receive_ok_flag == ){
            usart6.receive_ok_flag = ;
            for(i = ;i < ;i ++){
                buffer[i] = tolower(usart6.receive_buffer[i]);
            }
            if(memcmp(buffer,"ledr",strlen("ledr")) == ){        //±È½Ï½ÓÊÕÊý¾Ý
                LED_RED_ON;
                LED_GREEN_OFF;
                LED_BLUE_OFF;
                i2c.write_nbyte(0x03,0X8F,buffer,strlen(buffer));   //i2c×ÜÏß·¢ËÍÊý¾Ý
            }
            if(memcmp(buffer,"ledg",strlen("ledg")) == ){
                LED_RED_OFF;
                LED_GREEN_ON;
                LED_BLUE_OFF;
                i2c.write_nbyte(0x03,0X8F,buffer,strlen(buffer));
            }
            if(memcmp(buffer,"ledb",strlen("ledb")) == ){
                LED_RED_OFF;
                LED_GREEN_OFF;
                LED_BLUE_ON;
                i2c.write_nbyte(0x03,0X8F,buffer,strlen(buffer));
            }
            for(i = ; i < ; i ++);
            i2c.read_nbyte(0x02,0x0F,i2c_buffer,0x06);            //i2c×ÜÏß½ÓÊÕÊý¾Ý
            usart6.printf(i2c_buffer);
        }
  }
  /* USER CODE END 3 */

}

module i2c_ctrl(
    input clk_25m,
    input rst_n,
    input scl,
    inout sda,
    output led_red,
    output led_green,
    output led_blue
);

//---------------------------parameter--------------------------//
parameter ledr = {'d108,8'd101,'d100,8'd114,'d13},
             ledg = {'d108,8'd101,'d100,8'd103,'d13},
             ledb = {'d108,8'd101,'d100,8'd98,'d13},
             GINGKO = {'d71,8'd73,'d78,8'd71,'d75,8'd79},
             wide = 'd40;

//-----------------------------address--------------------------//
reg[:]m;
reg[:]device_address,word_address;                           //接收地址先传输高位

always@(posedge scl or negedge rst_n)
    if(!rst_n)
        begin
            m <= 'd0;
            device_address <= 'd0;
            word_address <= 'd0;
            tx_en <= 'd0;
            tx_en <= 'd0;
        end
    else case(m)
            'd0,5'd1,'d2,5'd3,'d4,5'd5,'d6,5'd7:                    //接收设备地址
                begin
                    if(!rx_en || !tx_en)
                        begin
                            m <= m + 'd1;
                            device_address <= {device_address[:],sda};
                        end
                    else m <= 'd0;
                end
            'd8:
                begin
                    if(device_address == 'd3 || device_address == 8'd2)
                        begin
                            m <= 'd9;
                            device_address <= 'd0;
                        end
                    else if(rx_ack || tx_ack)
                        begin
                            m <= 'd18;
                            device_address <= 'd0;
                        end
                    else
                        begin
                            m <= 'd0;
                        end
                end
            'd9,5'd10,'d11,5'd12,'d13,5'd14,'d15,5'd16:            //接收寄存器地址，以寄存器地址区分读写操作
                begin
                    m <= m + 'd1;
                    word_address <= {word_address[:],sda};
                end
            'd17:
                begin
                    if(word_address == 'h8f)                                //使能接收数据
                        begin
                            rx_en <= 'd1;
                            word_address <= 'd0;
                        end
                    else if(word_address == 'h0f)                         //使能发送数据
                        begin
                            tx_en <= 'd1;
                            word_address <= 'd0;
                        end
                    else if(rx_ack)
                        begin
                            rx_en <= 'd0;
                            m <= 'd0;
                        end
                    else if(tx_ack)
                        begin
                            tx_en <= 'd0;
                            m <= 'd18;
                        end
                    else m <= 'd17;
                end
            'd18:begin
                        m <= 'd0;
                    end
            endcase        

//-------------------------------rx---------------------------//
/*接收数据*/
reg[:]data_in;
reg[:]data;
reg[:]i;
reg tx_en,rx_en;
reg rx_ack;

always@(posedge scl or negedge rst_n)
    if(!rst_n)
        begin
            i <= 'd0;
            data <= 'd0;
            data_in <= 'd0;
            rx_ack <= 'd0;
        end
    else if(rx_en)
        begin
            case(i)
                'd0,5'd1,'d2,5'd3,'d4,5'd5,'d6,5'd7:        //移位完成数据接收
                    begin
                        i <= i + 'd1;
                        rx_ack <= 'd0;
                        data_in <= {data_in[:],sda};
                    end
                'd8:
                    begin
                        if(data_in[:] == 'h0d)
                            begin
                                i <= 'd9;
                                rx_ack <= 'd1;
                                data <= data_in;
                            end
                        else
                            begin
                                i <= 'd0;
                            end
                    end
                'd9:begin
                        rx_ack <= 'd0;
                        i <= 'd0;
                      end
                default:i <= 'd0;
            endcase
        end    

//-----------------------------data-------------------------//
/*比较接收数据*/
reg [:]led;
always@(posedge clk_25m or negedge rst_n)
    if(!rst_n)
        begin
            led <= 'b101;
        end
    else if (data[wide-:] == ledr)
            led <= 'b011;
    else if (data[wide-:] == ledg)
            led <= 'b101;
    else if (data[wide-:] == ledb)
            led <= 'b110;    

assign {led_red,led_green,led_blue} = led;    

//----------------------------tx--------------------------//        //发送数据   先传输高位
reg[:]data_out;
reg[:]j;
reg send_data;
reg tx_ack;
reg[:]tx_cnt;
always@(negedge scl or negedge rst_n)
    if(!rst_n)
        begin
            j <= 'd0;
            send_data <= 'd1;
            tx_ack <= 'd0;
            tx_cnt <= 'd0;
            data_out <= GINGKO;
        end
    else case(j)
                'd0,4'd1,'d2,4'd3,'d4,4'd5,'d6,4'd7:        //移位输出数据
                    begin
                        if(tx_en)
                            begin
                                j <= j + 'd1;
                                {send_data,data_out[:]} <= data_out;
                                tx_ack <= 'd0;
                            end
                    end
                'd8:begin
                        if(tx_cnt == 'd5)                            //判断最后一个字节，停止发送
                            begin
                                j <= j + 'd1;
                                tx_ack <= 'd1;
                                tx_cnt <= 'd0;
                            end
                        else
                            begin
                                j <= 'd0;
                                tx_ack <= 'd0;
                                tx_cnt <= tx_cnt + 'd1;
                            end
                    end
                'd9:begin
                            j <= 'd0;
                            tx_ack <= 'd0;
                            data_out <= GINGKO;
                    end
                'd10:begin
                            j <= 'd0;
                            tx_ack <= 'd0;
                        end
            endcase    

assign sda = (j >= 'd1 && j <= 4'd8) ? send_data : 'dz;

endmodule

源代码下载链接：

链接：http://pan.baidu.com/s/1geWgggF 密码：an3s

iCore4链接：