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温度计 [2017/03/13 10:28]
zhijun 		温度计 [2021/08/18 09:00] (当前版本)
gongyusu
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-======基于小脚丫STEP MXO2的温度显示系统====== +## 基于小脚丫STEP MXO2的温度显示系统 
-=====一、项目简介=====+ 
 +### 1、项目简介
 基于小脚丫STEP MXO2的温度显示系统的核心控制模块为小脚丫STEP MXO2开发板，采用由MicroUSB输入的5V供电，温度传感器选用的是DALLAS的经典传感器——DS18B20，一个封装和常见三极管（TO-92）相同的温度传感器，而显示模块采用LCD1602，相信读者对这两个模块一定是极为熟悉。 基于小脚丫STEP MXO2的温度显示系统的核心控制模块为小脚丫STEP MXO2开发板，采用由MicroUSB输入的5V供电，温度传感器选用的是DALLAS的经典传感器——DS18B20，一个封装和常见三极管（TO-92）相同的温度传感器，而显示模块采用LCD1602，相信读者对这两个模块一定是极为熟悉。
  
-=====二、项目框图=====+--- 
 + 
 +### 2、项目框图
 {{ ::​框图.png ?600 |}} {{ ::​框图.png ?600 |}}
-====1.控制核心====+ 
 +#### 2.1 控制核心 
 温度计项目控制核心为小脚丫STEP MXO2 V2版本FPGA开发板，FPGA芯片为Lattice Semiconductor的MachXO2 400HC系列FPGA。 温度计项目控制核心为小脚丫STEP MXO2 V2版本FPGA开发板，FPGA芯片为Lattice Semiconductor的MachXO2 400HC系列FPGA。
-====2.温度采集模块====+ 
 +#### 2.2 温度采集模块
 温度采集模块采用Dallas的经典产品——DS18B20，是一个高精度，占用空间小，硬件连接简单，价格低廉的数字温度传感器，采用单总线驱动方式，更为节省开发板资源。 温度采集模块采用Dallas的经典产品——DS18B20，是一个高精度，占用空间小，硬件连接简单，价格低廉的数字温度传感器，采用单总线驱动方式，更为节省开发板资源。
-====3.温度显示系统====+ 
 +#### 2.3 温度显示系统
 温度显示模块采用集成了ASCII字库的LCD1602，省去了自建字库的麻烦。 温度显示模块采用集成了ASCII字库的LCD1602，省去了自建字库的麻烦。
  
-=====三、硬件电路图=====+--- 
 +### 3、硬件电路图
 {{ ::​电路图.png?​800 |}} {{ ::​电路图.png?​800 |}}
 +温度计的硬件电路比较简单，首先在供电方面，作为控制核心的小脚丫开发板由于具备完善的下载与供电方案，故不必在设计下载电路，只需要一根MicroUSB数据线即可满足整体系统的供电与下载；
 +
 +在温度采集部分，DS18B20共有三个引脚，我们参照硬件手册，可发现该芯片的1号引脚接地，2号引脚为数据信号DQ，接到小脚丫的任意引脚上（下图接到了小脚丫STEP MXO2的“SI”引脚上），3号引脚为电源脚，参照手册，DS18B20的输入电压为3.0V-5.5V，此处我们采用了3.3V供电。
 +
 +温度显示部分，LCD1602共有16个引脚，下图为LCD1602的引脚简介，对应连接即可：
 +{{ ::​lcd1602引脚定义.png?​400 |}}
 +
 +---
 +### 4、Verilog代码
 +
 +#### 4.1 Verilog代码:​LCD1602显示部分
 +<code verilog>
 +// --------------------------------------------------------------------
 +// >>>>>>>>>>>>>>>>>>>>>>>>>​ COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<​
 +// --------------------------------------------------------------------
 +// Module:​LCD1602 ​
 +// 
 +// Author: STEP
 +// 
 +// Description:​ Display the temperature by LCD1602
 +// 
 +// Web: www.stepfpga.com
 +//     
 +// --------------------------------------------------------------------
 +// Code Revision History :
 +// --------------------------------------------------------------------
 +// Version: |Mod. Date:   ​|Changes Made:
 +// V1.0     ​|2017.3.8 ​    ​|Initial ver
 +// --------------------------------------------------------------------
 +
 +module LCD_1602(clk,​LCD_EN,​RS,​RW,​DB8,​one_wire,​rst);​
 +
 + input ​  ​clk,​rst; ​       //​系统时钟与复位，系统时钟==12M
 + output ​ LCD_EN;​ //​LCD_EN为LCD模块的使能信号（下降沿触发）
 + output ​ RS;​ //​RS=0时为写指令；RS=1时为写数据
 + output ​ RW;​ //​RW=0时对LCD模块执行写操作；RW=1时对LCD模块执行读操作
 + output ​ [7:0] DB8; //​8位指令或数据总线
 + inout one_wire;​ //​例化DS18B20模块单总线
 +
 + reg    RS;
 + reg LCD_EN_Sel;​
 + reg [7:0] DB8;
 + reg [127:​0] data_row1;​
 + reg [127:​0] data_row2;​
 +
 + reg [7:​0] result_unit;​
 + reg [7:0] result_decade;​
 + reg [7:0]   ​result_hundred;​
 + reg [7:0]   ​result_dec;​
 + reg [7:​0] result_dec2;​
 + reg [7:​0] result_dec3;​
 + reg [7:0] result_dec4;​
 + reg [7:0] sign;
 +
 + reg [3:0] num_unit;
 + reg [3:0] num_decade;
 + reg [3:0] num_hundred;​
 + reg [3:0] num_dec;
 + reg [3:0] num_dec2;
 + reg [3:0] num_dec3;
 + reg [3:0] num_dec4;​ //​若想显示小数点第四位，添加至显示内容并调整即可
 +
 + reg[19:0] cnt_ref;​ //​LCD1602更新计数器
 + reg ref;​ //​更新标志位
 +
 + always@(posedge clk_2ms) //​产生LCD1602更新所需信号
 + begin
 + if(cnt_ref==220) ​
 + begin
 + cnt_ref<​=0;​
 + ref<​=1;​
 + ref<​=0;​
 + end
 + else ​
 + begin
 + cnt_ref<​=cnt_ref+1;​
 + ref<​=1;​
 + end
 + end
 +
 + always@(*) //​1602输入数据接口处理
 + begin
 + case(num_unit) //​个位
 + 4'​d0:​result_unit<​=8'​b00110000;​
 + 4'​d1:​result_unit<​=8'​b00110001;​
 + 4'​d2:​result_unit<​=8'​b00110010;​
 + 4'​d3:​result_unit<​=8'​b00110011;​
 + 4'​d4:​result_unit<​=8'​b00110100;​
 + 4'​d5:​result_unit<​=8'​b00110101;​
 + 4'​d6:​result_unit<​=8'​b00110110;​
 + 4'​d7:​result_unit<​=8'​b00110111;​
 + 4'​d8:​result_unit<​=8'​b00111000;​
 + 4'​d9:​result_unit<​=8'​b00111001;​
 + default:​result_unit<​=result_unit;​
 + endcase
 +
 + case(num_decade) //​十位
 + 4'​d0:​result_decade<​=8'​b00110000;​
 + 4'​d1:​result_decade<​=8'​b00110001;​
 + 4'​d2:​result_decade<​=8'​b00110010;​
 + 4'​d3:​result_decade<​=8'​b00110011;​
 + 4'​d4:​result_decade<​=8'​b00110100;​
 + 4'​d5:​result_decade<​=8'​b00110101;​
 + 4'​d6:​result_decade<​=8'​b00110110;​
 + 4'​d7:​result_decade<​=8'​b00110111;​
 + 4'​d8:​result_decade<​=8'​b00111000;​
 + 4'​d9:​result_decade<​=8'​b00111001;​
 + default:​result_decade<​=result_decade;​
 + endcase
 +
 + case(num_hundred) //​百位
 + 4'​d0:​result_hundred<​=8'​b00110000;​
 + 4'​d1:​result_hundred<​=8'​b00110001;​
 + 4'​d2:​result_hundred<​=8'​b00110010;​
 + 4'​d3:​result_hundred<​=8'​b00110011;​
 + 4'​d4:​result_hundred<​=8'​b00110100;​
 + 4'​d5:​result_hundred<​=8'​b00110101;​
 + 4'​d6:​result_hundred<​=8'​b00110110;​
 + 4'​d7:​result_hundred<​=8'​b00110111;​
 + 4'​d8:​result_hundred<​=8'​b00111000;​
 + 4'​d9:​result_hundred<​=8'​b00111001;​
 + default:​result_hundred<​=result_hundred;​
 + endcase
 +
 + case(num_dec) //​小数位
 + 4'​d0:​result_dec<​=8'​b00110000;​
 + 4'​d1:​result_dec<​=8'​b00110001;​
 + 4'​d2:​result_dec<​=8'​b00110010;​
 + 4'​d3:​result_dec<​=8'​b00110011;​
 + 4'​d4:​result_dec<​=8'​b00110100;​
 + 4'​d5:​result_dec<​=8'​b00110101;​
 + 4'​d6:​result_dec<​=8'​b00110110;​
 + 4'​d7:​result_dec<​=8'​b00110111;​
 + 4'​d8:​result_dec<​=8'​b00111000;​
 + 4'​d9:​result_dec<​=8'​b00111001;​
 + default:​result_dec<​=result_dec;​
 + endcase
 +
 + case(num_dec4) //​小数位
 + 4'​d0:​result_dec4<​=8'​b00110000;​
 + 4'​d1:​result_dec4<​=8'​b00110001;​
 + 4'​d2:​result_dec4<​=8'​b00110010;​
 + 4'​d3:​result_dec4<​=8'​b00110011;​
 + 4'​d4:​result_dec4<​=8'​b00110100;​
 + 4'​d5:​result_dec4<​=8'​b00110101;​
 + 4'​d6:​result_dec4<​=8'​b00110110;​
 + 4'​d7:​result_dec4<​=8'​b00110111;​
 + 4'​d8:​result_dec4<​=8'​b00111000;​
 + 4'​d9:​result_dec4<​=8'​b00111001;​
 + default:​result_dec4<​=result_dec4;​
 + endcase
 +
 + case(num_dec2) //​小数位
 + 4'​d0:​result_dec2<​=8'​b00110000;​
 + 4'​d1:​result_dec2<​=8'​b00110001;​
 + 4'​d2:​result_dec2<​=8'​b00110010;​
 + 4'​d3:​result_dec2<​=8'​b00110011;​
 + 4'​d4:​result_dec2<​=8'​b00110100;​
 + 4'​d5:​result_dec2<​=8'​b00110101;​
 + 4'​d6:​result_dec2<​=8'​b00110110;​
 + 4'​d7:​result_dec2<​=8'​b00110111;​
 + 4'​d8:​result_dec2<​=8'​b00111000;​
 + 4'​d9:​result_dec2<​=8'​b00111001;​
 + default:​result_dec2<​=result_dec2;​
 + endcase
 +
 + case(num_dec3) //​小数位
 + 4'​d0:​result_dec3<​=8'​b00110000;​
 + 4'​d1:​result_dec3<​=8'​b00110001;​
 + 4'​d2:​result_dec3<​=8'​b00110010;​
 + 4'​d3:​result_dec3<​=8'​b00110011;​
 + 4'​d4:​result_dec3<​=8'​b00110100;​
 + 4'​d5:​result_dec3<​=8'​b00110101;​
 + 4'​d6:​result_dec3<​=8'​b00110110;​
 + 4'​d7:​result_dec3<​=8'​b00110111;​
 + 4'​d8:​result_dec3<​=8'​b00111000;​
 + 4'​d9:​result_dec3<​=8'​b00111001;​
 + default:​result_dec3<​=result_dec3;​
 + endcase
 + end  ​
 +
 +//​-------------------------------------//​
 +//​输入时钟12MHz ​ 输出周期2ms
 +//​division12MHz_2ms.v
 + reg [15:​0]count;​
 + reg clk_2ms;
 + always @ (posedge clk)
 + begin
 + if(count == 16'​d12_000)
 + begin
 + count <= 16'b1;
 + clk_2ms <= ~clk_2ms;
 + end
 + else  ​
 + count <= count + 1'b1;
 + end
 +//​---------------------------------------//​
 +
 + reg     ​[127:​0] Data_Buf; ​  ​ //​液晶显示的数据缓存
 + reg     [4:0] disp_count;​
 + reg     [3:0] state;​ //​状态机
 +
 + parameter ​  ​Clear_Lcd = 4'​b0000; ​ //​清屏并光标复位 ​
 + parameter Set_Disp_Mode = 4'​b0001;​ //​设置显示模式：8位2行5x7点阵 ​  
 + parameter Disp_On = 4'​b0010;​ //​显示器开、光标不显示、光标不允许闪烁
 + parameter Shift_Down = 4'​b0011; ​ //​文字不动，光标自动右移
 + parameter Write_Addr = 4'​b0100; ​  ​ //​写入显示起始地址
 + parameter Write_Data_First = 4'​b0101;​ //​写入第一行显示的数据 ​    
 + parameter Write_Data_Second = 4'​b0110;​ //​写入第二行显示的数据
 + assign ​ RW = 1'​b0; ​ //​RW=0时对LCD模块执行写操作(一直保持写状态）
 + assign ​ LCD_EN = LCD_EN_Sel ? clk_2ms : 1'​b0;​ //​通过LCD_EN_Sel信号来控制LCD_EN的开启与关闭
 +
 +
 +//​--------------------------------显示模块----------------------------//​
 + always @(posedge clk_2ms ​ or negedge rst  or negedge ref)
 + begin
 +    //​-----------------------复位并更新显示数据--------------------//​
 +
 + if(!rst || !ref)
 + begin
 + state <= Clear_Lcd; ​ //​复位：清屏并光标复位 ​  
 + RS <= 1'​b1; ​         //​复位：RS=1时为读指令； ​                      
 + DB8 <= 8'​b0; ​        ​ //​复位：使DB8总线输出全0
 + LCD_EN_Sel <= 1'​b0; ​ //​复位：关夜晶使能信号
 + disp_count <= 5'​b0;​
 + data_row1 <= {   ​ //​输入第一行要显示的数据
 + 8'​b01010011, ​   //S
 + 8'​b01010100,​ //​T
 + 8'​b01000101,​ //​E
 + 8'​b01010000,​ //​P
 + 8'​b00100000,​ //​SPACE
 + 8'​b01000110,​ //​F
 + 8'​b01010000,​ //​P
 + 8'​b01000111,​ //​G
 + 8'​b01000001,​ //​A
 + 8'​b00100000,​ //​SPACE
 + 8'​b00100000,​ //​SPACE
 + 8'​b00100000,​ //​SPACE
 + 8'​b00100000,​ //​SPACE
 + 8'​b00100000, ​     //​SPACE ​     ​
 + 8'​b00100000,​ //​SPACE
 + 8'​b00100000 //​SPACE
 + };
 + data_row2 <= { 8'​b00100000,​ //​输入第二行要显示的数据
 + 8'​b00100000,​ //​SPACE
 + 8'​b01010100,​ //T
 + 8'​b01100101,​ //​e
 + 8'​b01101101,​ //m
 + 8'​b00111010,​ //​冒号
 + sign,​
 + result_unit,​
 + result_decade, ​        
 + result_hundred, ​       ​
 + 8'​b00101110,​ //​.
 + result_dec, ​       ​
 + result_dec2, ​   ​
 + result_dec3,​
 + 8'​hdf,​ //​℃
 + 8'​b01000011
 +
 + };
 + end
 + else ​
 + begin
 + case(state)  ​
 +//​-------------------------------初始化LCD------------------------------------// ​      
 +
 +     Clear_Lcd : begin LCD_EN_Sel <= 1'​b1;​ //​开使能
 +  ​ RS <= 1'​b0;​ //​写指令
 +  ​ DB8 <= 8'​b00000001; ​ //​清屏并光标复位
 +  ​     state <= Set_Disp_Mode;​ end
 + Set_Disp_Mode : begin DB8 <= 8'​b00111000; ​ //​设置显示模式：8位2行5x8点阵 ​
 +  ​ state <= Disp_On; ​      end
 +   Disp_On : begin DB8 <= 8'​b00001100; ​  ​ //​显示器开、光标不显示、光标不允许闪烁 ​
 +  ​ state <= Shift_Down;​  ​ end
 +    ​Shift_Down : begin DB8 <= 8'​b00000110; ​   //​文字不动，光标自动右移 ​   ​
 +  ​ state <= Write_Addr; ​   end
 +   ​
 +//​---------------------------------显示循环------------------------------------//​
 +    
 +    ​Write_Addr : begin RS <= 1'​b0;​ //​写指令
 +  ​ DB8 <= 8'​b10000000; ​    //​写入第一行显示起始地址：第一行第1个位置 ​   ​
 +  ​ Data_Buf <= data_row1; ​    ​ //​将第一行显示的数据赋给Data_First_Buf
 +  ​     state <= Write_Data_First;​ end
 + Write_Data_First : begin //​写第一行数据
 + if(disp_count == 16)    //​disp_count等于15时表示第一行数据已写完
 + begin
 + RS <= 1'​b0;​ //​写指令
 + DB8 <= 8'​b11000000; ​    //​送入写第二行的指令,​第2行第1个位置
 + disp_count <= 5'b0; //​计数清0
 + Data_Buf ​  <= data_row2;​ //​将第2行显示的数据赋给Data_First_Buf
 + state ​    <= Write_Data_Second;​end ​  //​写完第一行进入写第二行状态
 + else //​没写够16字节
 + begin
 + RS <= 1'​b1; ​   //​RS=1表示写数据
 + DB8 <= Data_Buf[127:​120];​
 + Data_Buf <= (Data_Buf << 8);
 + disp_count <= disp_count + 1'b1;
 + state <= Write_Data_First;​ end end
 + Write_Data_Second : begin //​写第二行数据
 + if(disp_count == 16)//​数据发送完毕
 + begin
 + RS <= 1'​b0;​ //​写指令
 + DB8 <= 8'​b10000000; ​    //​写入第一行显示起始地址：第一行第1个位置
 + disp_count <= 5'​b0; ​
 + state <= Write_Addr; ​  ​ //​重新循环
 + end
 + else
 + begin
 + RS <= 1'b1;
 + DB8 <= Data_Buf[127:​120];​
 + Data_Buf <= (Data_Buf << 8);
 + disp_count <= disp_count + 1'b1;
 + state <= Write_Data_Second; ​
 + end end
 +//​--------------------------------------------------------------------------//​
 +   default :  state <= Clear_Lcd; //​若state为其他值，则将state置为Clear_Lcd ​
 + endcase ​
 + end
 + end
 +
 +//​--------------------------------------------------------------------------//​
 +
 +
 +
 +wire clk_in;
 +wire rst_n_in;
 +wire [15:0] data_out;
 +wire tem_flag=data_out[15:​11]?​1'​b0:​1'​b1;​
 +wire [10:0] tem_code=tem_flag?​data_out[10:​0]:​(~data_out[10:​0])+1'​b1; ​
 +wire [20:0] tem_data=tem_code*625;​
 +reg [27:0] bcd_code;
 +DS18B20Z DS18B20Z_uut
 +(    ​
 +.one_wire(one_wire),​
 +.clk_in(clk),​
 +.rst_n_in(rst),​
 +.data_out(data_out)
 +);
 +
 +
 +
 + reg [48:0] shift_reg; ​  
 +always@(posedge clk or negedge rst)begin ​     ​
 +
 + shift_reg= {28'​h0,​tem_data}; ​
 +
 + if(!rst) bcd_code = 0;      ​
 + else 
 + begin ​        
 + repeat(21)//​repeat B_SIZE times
 + begin ​                               ​
 + if (shift_reg[24:​21] >= 5) shift_reg[24:​21] = shift_reg[24:​21] + 2'b11;
 + if (shift_reg[28:​25] >= 5) shift_reg[28:​25] = shift_reg[28:​25] + 2'b11;
 + if (shift_reg[32:​29] >= 5) shift_reg[32:​29] = shift_reg[32:​29] + 2'b11;
 + if (shift_reg[36:​33] >= 5) shift_reg[36:​33] = shift_reg[36:​33] + 2'b11;
 + if (shift_reg[40:​37] >= 5) shift_reg[40:​37] = shift_reg[40:​37] + 2'b11;
 + if (shift_reg[44:​41] >= 5) shift_reg[44:​41] = shift_reg[44:​41] + 2'b11;
 + if (shift_reg[48:​45] >= 5) shift_reg[48:​45] = shift_reg[48:​45] + 2'b11;
 + if (tem_flag==0) sign<​=8'​b00101101;​
 + if (tem_flag==1) sign<​=8'​b00100000;​
 + shift_reg = shift_reg << 1; 
 + end ​        
 + bcd_code=shift_reg[48:​21]; ​  
 +
 + num_unit <​= bcd_code[27:​24];​
 + num_decade <​= bcd_code[23:​20];​
 + num_hundred<​= bcd_code[19:​16];​
 + num_dec <​= bcd_code[15:​12];​
 + num_dec2 <​= ​ bcd_code[11:​8];​
 + num_dec3 <​= ​ bcd_code[7:​4];​
 + num_dec4 <​= ​ bcd_code[3:​0];​
 +
 +
 + end  ​
 +end
 +    ​
 +endmodule
 +
 +</​code>​
 +
 +---
 +#### 4.2 温度采集部分
 +<code verilog>
 +// --------------------------------------------------------------------
 +// >>>>>>>>>>>>>>>>>>>>>>>>>​ COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<​
 +// --------------------------------------------------------------------
 +// Module:​DS18B20Z ​
 +// 
 +// Author: Step
 +// 
 +// Description:​ Drive DS18B20Z to get temperature code
 +// 
 +// Web: www.stepfpga.com
 +// 
 +// --------------------------------------------------------------------
 +// Code Revision History :
 +// --------------------------------------------------------------------
 +// Version: |Mod. Date:   ​|Changes Made:
 +// V1.0     ​|2015/​11/​11 ​  ​|Initial ver
 +// --------------------------------------------------------------------
 +module DS18B20Z
 +(
 + input clk_in,​ //​ system clock
 + input rst_n_in,​ //​ system reset, active low
 + inout one_wire,​ //​ ds18b20z one-wire-bus
 + output reg [15:​0] data_out //​ ds18b20z data_out
 +);
 +
 +
 +    
 +
 + localparam IDLE = 3'​d0;​
 + localparam MAIN = 3'​d1;​
 + localparam INIT = 3'​d2;​
 + localparam WRITE = 3'​d3;​
 + localparam READ = 3'​d4;​
 + localparam DELAY = 3'​d5;​
 +
 + //generate clk_1mhz clock
 + reg clk_1mhz;​
 + reg [2:​0] cnt_1mhz;​
 + always@(posedge clk_in or negedge rst_n_in) begin
 + if(!rst_n_in) begin
 + cnt_1mhz <= 3'd0;
 + clk_1mhz <= 1'b0;
 + end else if(cnt_1mhz >= 3'd5) begin
 + cnt_1mhz <= 3'd0;
 + clk_1mhz <= ~clk_1mhz;
 + end else begin
 + cnt_1mhz <= cnt_1mhz + 1'b1;
 + end
 + end
 +
 + reg one_wire_buffer;​
 + reg [3:​0] cnt_main;​
 + reg [7:​0] data_wr;​
 + reg [7:​0] data_wr_buffer;​
 + reg [2:​0] cnt_init;​
 + reg [19:​0] cnt_delay;​
 + reg [19:​0] num_delay;​
 + reg [5:​0] cnt_write;​
 + reg [5:​0] cnt_read;​
 + reg [15:​0] temperature;​
 + reg [7:​0] temperature_buffer;​
 + reg [2:0] state = IDLE;
 + reg [2:0] state_back = IDLE;
 + always@(posedge clk_1mhz or negedge rst_n_in) begin
 + if(!rst_n_in) begin
 + state <= IDLE;
 + state_back <= IDLE;
 + cnt_main <= 4'd0;
 + cnt_init <= 3'd0;
 + cnt_write <= 6'd0;
 + cnt_read <= 6'd0;
 + cnt_delay <= 20'd0;
 + one_wire_buffer <= 1'bz;
 + temperature <= 16'h0;
 + end else begin
 + case(state)
 + IDLE:​begin
 + state <= MAIN;
 + state_back <= MAIN;
 + cnt_main <= 4'd0;
 + cnt_init <= 3'd0;
 + cnt_write <= 6'd0;
 + cnt_read <= 6'd0;
 + cnt_delay <= 20'd0;
 + one_wire_buffer <= 1'bz;
 + end
 + MAIN:​begin
 + if(cnt_main >= 4'd11) cnt_main <= 1'b0;
 + else cnt_main <= cnt_main + 1'b1;
 + case(cnt_main)
 + 4'​d0:​ begin state <= INIT; end
 + 4'​d1:​ begin data_wr <= 8'​hcc;​state <= WRITE; end
 + 4'​d2:​ begin data_wr <= 8'​h44;​state <= WRITE; end
 + 4'​d3:​ begin num_delay <= 20'​d750000;​state <= DELAY;​state_back <= MAIN; end
 +
 + 4'​d4:​ begin state <= INIT; end
 + 4'​d5:​ begin data_wr <= 8'​hcc;​state <= WRITE; end
 + 4'​d6:​ begin data_wr <= 8'​hbe;​state <= WRITE; end
 +
 + 4'​d7:​ begin state <= READ; end
 + 4'​d8:​ begin temperature[7:​0] <= temperature_buffer;​ end
 +
 + 4'​d9:​ begin state <= READ; end
 + 4'​d10:​ begin temperature[15:​8] <= temperature_buffer;​ end
 +
 + 4'​d11:​ begin state <= IDLE;​data_out <= temperature;​ end
 + default:​ state <= IDLE;
 + endcase
 + end
 + INIT:​begin
 + if(cnt_init >= 3'd6) cnt_init <= 1'b0;
 + else cnt_init <= cnt_init + 1'b1;
 + case(cnt_init)
 + 3'​d0:​ begin one_wire_buffer <= 1'b0; end
 + 3'​d1:​ begin num_delay <= 20'​d500;​state <= DELAY;​state_back <= INIT; end
 + 3'​d2:​ begin one_wire_buffer <= 1'bz; end
 + 3'​d3:​ begin num_delay <= 20'​d100;​state <= DELAY;​state_back <= INIT; end
 + 3'​d4:​ begin if(one_wire) state <= IDLE; else state <= INIT; end
 + 3'​d5:​ begin num_delay <= 20'​d400;​state <= DELAY;​state_back <= INIT; end
 + 3'​d6:​ begin state <= MAIN; end
 + default:​ state <= IDLE;
 + endcase
 + end
 + WRITE:​begin
 + if(cnt_write >= 6'd50) cnt_write <= 1'b0;
 + else cnt_write <= cnt_write + 1'b1;
 + case(cnt_write)
 + //​lock data_wr
 + 6'​d0:​ begin data_wr_buffer <= data_wr; end
 + //​write bit 0
 + 6'​d1:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d2:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d3:​ begin one_wire_buffer <= data_wr_buffer[0];​ end
 + 6'​d4:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d5:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d6:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 1
 + 6'​d7:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d8:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d9:​ begin one_wire_buffer <= data_wr_buffer[1];​ end
 + 6'​d10:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d11:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d12:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 2
 + 6'​d13:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d14:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d15:​ begin one_wire_buffer <= data_wr_buffer[2];​ end
 + 6'​d16:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d17:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d18:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 3
 + 6'​d19:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d20:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d21:​ begin one_wire_buffer <= data_wr_buffer[3];​ end
 + 6'​d22:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d23:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d24:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 4
 + 6'​d25:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d26:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d27:​ begin one_wire_buffer <= data_wr_buffer[4];​ end
 + 6'​d28:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d29:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d30:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 5
 + 6'​d31:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d32:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d33:​ begin one_wire_buffer <= data_wr_buffer[5];​ end
 + 6'​d34:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d35:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d36:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 6
 + 6'​d37:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d38:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d39:​ begin one_wire_buffer <= data_wr_buffer[6];​ end
 + 6'​d40:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d41:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d42:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​write bit 7
 + 6'​d43:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d44:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d45:​ begin one_wire_buffer <= data_wr_buffer[7];​ end
 + 6'​d46:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d47:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d48:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= WRITE; end
 + //​back to main
 + 6'​d49:​ begin num_delay <= 20'​d80;​state <= DELAY;​state_back <= WRITE; end
 + 6'​d50:​ begin state <= MAIN; end
 + default:​ state <= IDLE;
 + endcase
 + end
 + READ:​begin
 + if(cnt_read >= 6'd48) cnt_read <= 1'b0;
 + else cnt_read <= cnt_read + 1'b1;
 + case(cnt_read)
 + //​read bit 0
 + 6'​d0:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d1:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d2:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d3:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d4:​ begin temperature_buffer[0] <= one_wire; end
 + 6'​d5:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 1
 + 6'​d6:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d7:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d8:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d9:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d10:​ begin temperature_buffer[1] <= one_wire; end
 + 6'​d11:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 2
 + 6'​d12:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d13:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d14:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d15:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d16:​ begin temperature_buffer[2] <= one_wire; end
 + 6'​d17:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 3
 + 6'​d18:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d19:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d20:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d21:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d22:​ begin temperature_buffer[3] <= one_wire; end
 + 6'​d23:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 4
 + 6'​d24:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d25:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d26:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d27:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d28:​ begin temperature_buffer[4] <= one_wire; end
 + 6'​d29:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 5
 + 6'​d30:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d31:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d32:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d33:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d34:​ begin temperature_buffer[5] <= one_wire; end
 + 6'​d35:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 6
 + 6'​d36:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d37:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d38:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d39:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d40:​ begin temperature_buffer[6] <= one_wire; end
 + 6'​d41:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​read bit 7
 + 6'​d42:​ begin one_wire_buffer <= 1'b0; end
 + 6'​d43:​ begin num_delay <= 20'​d2;​state <= DELAY;​state_back <= READ; end
 + 6'​d44:​ begin one_wire_buffer <= 1'bz; end
 + 6'​d45:​ begin num_delay <= 20'​d10;​state <= DELAY;​state_back <= READ; end
 + 6'​d46:​ begin temperature_buffer[7] <= one_wire; end
 + 6'​d47:​ begin num_delay <= 20'​d55;​state <= DELAY;​state_back <= READ; end
 + //​back to main
 + 6'​d48:​ begin state <= MAIN; end
 + default:​ state <= IDLE;
 + endcase
 + end
 + DELAY:​begin
 + if(cnt_delay >= num_delay) begin
 + cnt_delay <= 1'b0;
 + state <= state_back; ​
 + end else cnt_delay <= cnt_delay + 1'b1;
 + end
 + endcase
 + end
 + end
 +
 + assign one_wire = one_wire_buffer;​
 +
 +endmodule
 +</​code>​