47.简易电压表的设计与验证（2）

（1）Verilog 代码：

module adc_collect(
    input                   clk         ,
    input                   reset_n     ,
    input   [7:0]           adc_data    ,
    
    output                  clk_adc     
    
);
    wire                clk_adc_a       ;
    wire                clk_adc_turn    ;
    wire                locked          ;
    wire    [31:0]      n_volt          ;
    wire    [31:0]      p_volt          ;
    wire    [31:0]      data_n          ;
    wire    [31:0]      data_p          ;
    
    reg     [10:0]      ad_cnt          ;
    reg     [19:0]      sum_ad          ;
    reg     [27:0]      adc_mid         ;
    reg     [31:0]      volt_n          ;
    reg     [31:0]      volt_p          ;
    
 assign clk_adc = clk_adc_a  ; 
 
pll_20M         pll_20M_inst
(
    .clk_adc(clk_adc_a),                  // output clk_adc
    .clk_adc_turn(clk_adc_turn),        // output clk_adc_turn
    .resetn(reset_n),                    // input resetn
    .locked(locked),                    // output locked
    .clk(clk)                           // input clk
);      
 
ila_volt        ila_volt_inst
(
	.clk(clk),                       // input wire clk
	.probe0(n_volt),                // input wire [31:0]  probe0  
	.probe1(p_volt)                 // input wire [31:0]  probe1
);
 
//adc累加计数器
always@(posedge clk_adc_turn or negedge locked)
    if(!locked)    
        ad_cnt  <= 11'd0;
    else if(ad_cnt == 11'd1025)
        ad_cnt  <= 11'd1025;
    else 
        ad_cnt  <= ad_cnt + 11'd1;
 
//adc前1024个数据累加       
always@(posedge clk_adc_turn or negedge locked)
    if(!locked)
        sum_ad <= 20'd0;
    else if(ad_cnt <= 11'd1024)
        sum_ad <= sum_ad + adc_data;
    else    
        sum_ad <= sum_ad;
 
//adc中值计算     
always@(posedge clk_adc_turn or negedge locked)
    if(!locked)
        adc_mid <= 28'd0;
    else if(ad_cnt == 11'd1024)
        adc_mid <= sum_ad >> 10;
    else if(ad_cnt == 11'd1025)
        adc_mid <= adc_mid;
    else 
        adc_mid <= 28'd0;
        
//精度定义   显示数据为4位数，其中第一位为个位，后三位为十分位，百分位，千分位。     40960_000 = 5* 2^13 * 1000
    assign data_n = (ad_cnt == 11'd1025)? 40960_000/(adc_mid + 1) : 0;
    assign data_p = (ad_cnt == 11'd1025)? 40960_000/(256 - adc_mid) : 0;    
        
//电压计算
always@(posedge clk_adc_turn or negedge locked)
    if(!locked)
        volt_n <= 32'd0;
    else if((ad_cnt == 11'd1025) && (adc_data < adc_mid))
        volt_n <= (data_n * (adc_mid - adc_data)) >> 13;
    else    
        volt_n <= 32'd0;
        
always@(posedge clk_adc_turn or negedge locked)
    if(!locked)
        volt_p <= 32'd0;
    else if((ad_cnt == 11'd1025) && (adc_data >= adc_mid))
        volt_p <= (data_n * (adc_data - adc_mid)) >> 13;
    else    
        volt_p <= 32'd0;   
 
//传入ILA
    assign n_volt = volt_n;
    assign p_volt = volt_p;
        
endmodule

（2）仿真文件：

`timescale 1ns / 1ps
 
module adc_collect_tb;
 
reg         clk         ;
reg         clk_sample  ;
reg         reset_n     ;
reg   [7:0] adc_data    ;
reg   [7:0] data_reg    ;
reg         data_en     ;
 
wire        clk_adc     ;
 
initial clk = 1'd1;
always #10 clk = ~clk;
initial clk_sample = 1'd1;
always #25 clk_sample = ~clk_sample;
 
initial begin
    reset_n <= 1'd0;
    #25;
    reset_n <= 1'd1;
    #200; 
    data_en <= 1'd0;
    #2000000;
    data_en <= 1'd1;    
    #2000000;
    $stop;
end
 
    always@(posedge clk_sample or negedge reset_n)
        if(!reset_n)
            data_reg <= 8'd0;
        else if(data_en)
            data_reg <= data_reg + 8'd1;
        else 
            data_reg <= 8'd0;
            
    always@(posedge clk_sample or negedge reset_n)
        if(!reset_n)
            adc_data <= 8'd0;
        else if(!data_en)
            adc_data <= 8'd125;
        else 
            adc_data <= data_reg ;
            
adc_collect     adc_collect_inst(
    .clk         (clk),
    .reset_n     (reset_n),
    .adc_data    (adc_data),
    .clk_adc     (clk_adc)
    
);
endmodule

（3）仿真波形（仿真前先把ILA注释掉）：

• 整体波形图：

• PLL时钟波形图：

  

• 求中值中，累加计数器和中间值的计算：

  

• 后续dac数据的赋值已经精度的波形：​​​​​​​
• 数值波形：

（4）XDC文件：

set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[1]}]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[6]}]
set_property IOSTANDARD LVCMOS33 [get_ports clk_adc]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[0]}]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[7]}]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[4]}]
set_property IOSTANDARD LVCMOS33 [get_ports reset_n]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[3]}]
set_property IOSTANDARD LVCMOS33 [get_ports clk]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[5]}]
set_property IOSTANDARD LVCMOS33 [get_ports {adc_data[2]}]
set_property PACKAGE_PIN W19 [get_ports clk]
set_property PACKAGE_PIN N15 [get_ports reset_n]
set_property PACKAGE_PIN L13 [get_ports {adc_data[0]}]
set_property PACKAGE_PIN M13 [get_ports {adc_data[1]}]
set_property PACKAGE_PIN M16 [get_ports {adc_data[2]}]
set_property PACKAGE_PIN M15 [get_ports {adc_data[3]}]
set_property PACKAGE_PIN M20 [get_ports {adc_data[4]}]
set_property PACKAGE_PIN N20 [get_ports {adc_data[5]}]
set_property PACKAGE_PIN M22 [get_ports {adc_data[6]}]
set_property PACKAGE_PIN N22 [get_ports {adc_data[7]}]
set_property PACKAGE_PIN L14 [get_ports clk_adc]

（5)实验现象：

编译遇到报错：

解决方法：

未接线，0v时，ILA波形： 

-2.3v时，ILA波形： 

-1.5v时，ILA波形：

0.5v时，ILA波形：

2.7v时，ILA波形：

3.75v时，ILA波形：

4.85v时，ILA波形：