FPGA(18) 实验综合13 RTC实时时钟

PCF8563简介

一款工业级多功能时钟/日历芯片，具有报警功能、定时器功能、时钟输出功能以及中断输出功能，能完成各种复杂的定时服务。

开始信号+ 7位地址+写操作+响应+写寄存器地址+响应信号+开始+7位地址+读操作+响应+0x02数据+响应+0x03数据+。。。。+非应答信号+停止信号

读出数据所用always

always @(posedge clk or negedge rst_n) begin
    if(!rst_n) begin
        sec        <= 8'h0;
        min        <= 8'h0;
        hour       <= 8'h0;
        day        <= 8'h0;
        mon        <= 8'h0;
        year       <= 8'h0;
        i2c_exec   <= 1'b0;
        i2c_rh_wl  <= 1'b0;
        i2c_addr   <= 8'd0;
        i2c_data_w <= 8'd0;
        flow_cnt   <= 4'd0;
        wait_cnt   <= 13'd0;
    end
    else begin
        i2c_exec <= 1'b0;
        case(flow_cnt)
            //上电初始化
            4'd0: begin
                if(wait_cnt == 13'd8000) begin
                    wait_cnt<= 12'd0;
                    flow_cnt<= flow_cnt + 1'b1;
                end
                else
                    wait_cnt<= wait_cnt + 1'b1;
            end
            //写读秒
            4'd1: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h02;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[7:0];
            end
            4'd2: begin
                if(i2c_done == 1'b1) begin
                    sec     <= i2c_data_r[6:0];
                    flow_cnt<= flow_cnt + 1'b1;
                end
            end
            //写读分
            4'd3: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h03;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[15:8];
            end
            4'd4: begin
                if(i2c_done == 1'b1) begin
                    min     <= i2c_data_r[6:0];
                    flow_cnt<= flow_cnt + 1'b1;
                end
            end
            //写读时
            4'd5: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h04;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[23:16];
            end
            4'd6: begin
                if(i2c_done == 1'b1) begin
                    hour    <= i2c_data_r[5:0];
                    flow_cnt<= flow_cnt + 1'b1;
                end
            end
            //写读天
            4'd7: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h05;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[31:24];
            end
            4'd8: begin
                if(i2c_done == 1'b1) begin
                    day     <= i2c_data_r[5:0];
                    flow_cnt<= flow_cnt + 1'b1;
                end
            end
            //写读月
            4'd9: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h07;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[39:32];
            end
            4'd10: begin
                if(i2c_done == 1'b1) begin
                    mon     <= i2c_data_r[4:0];
                    flow_cnt<= flow_cnt + 1'b1;
                end
            end
            //写读年
            4'd11: begin
                i2c_exec  <= 1'b1;
                i2c_addr  <= 8'h08;
                flow_cnt  <= flow_cnt + 1'b1;
                i2c_data_w<= TIME_INI[47:40];
            end
            4'd12: begin
                if(i2c_done == 1'b1) begin
                    year     <= i2c_data_r;
                    i2c_rh_wl<= 1'b1;
                    flow_cnt <= 4'd1;
                end
            end
            default: flow_cnt <= 4'd0;
        endcase
    end
end