重温FPGA设计流程(七、纯Verilog实现数字频率计)

软件：Vivado2017.4 板卡：Ego1 型号：xc7a35tcsg324-1
七、纯Verilog实现数字频率计

hz_counter_top.v

`timescale 1ns / 1ps

module hz_counter_top(
	input wire clk_100MHz,
	input wire clr,
	input wire sig_source,
	output wire[6:0]a_to_g,
	output wire[3:0]an
    );
	wire[16:0]p;
	wire clk_1Hz,clk_190Hz,clk_100kHz;
	wire[13:0]sig_Hz;
	
	clkdiv U1(.clk_100MHz(clk_100MHz),
				.clr(clr),
				.clk_100kHz(clk_100kHz),
				.clk_190Hz(clk_190Hz),
				.clk_1Hz(clk_1Hz)
				);
	hz_counter U2(.clk_100kHz(clk_100kHz),
					.clk_1Hz(clk_1Hz),
					.sig_source(sig_source),
					.sig_Hz(sig_Hz)
					);
	binbcd14 U3(.b(sig_Hz),
				.p(p)
				);
	x7segbc U4(.x(p[15:0]),
				.cclk(clk_190Hz),
				.clr(~clr),
				.a_to_g(a_to_g),
				.an(an)
				);
endmodule

clkdiv.v

`timescale 1ns / 1ps

module clkdiv(
	input wire clk_100MHz,
	input wire clr,
	output reg clk_100kHz,
	output wire clk_190Hz,
	output reg clk_1Hz
    );
	reg[25:0]count1,count2,count3;
	initial
		begin
			count1=0;
			count2=0;
			count3=0;
		end
	always@(posedge clk_100MHz)
		begin
			count3<=count3+1;
			if(count3==26'h1F4)
				begin
					count3<=0;
					clk_100kHz<=~clk_100kHz;
				end
		end
	always@(posedge clk_100MHz)
		begin
			count1<=count1+1;
			if(count1 == 26'h2FAF07F)
				begin	
					count1<=0;
					clk_1Hz<=~clk_1Hz;
				end
		end
	always@(posedge clk_100MHz or posedge clr)
		begin
			if(clr ==1)
				count2 <=0;
			else
				count2<=count2+1;
		end
	assign clk_190Hz =count2[18];
endmodule

hz_counter.v

`timescale 1ns / 1ps
module hz_counter(
	input wire clk_100kHz,
	input wire clk_1Hz,
	input wire sig_source,
	output reg[13:0]sig_Hz
    );
	parameter N=1000000;
	reg sig_state;
	reg[16:0]sig_Hz_reg;
	reg[16:0]sig_count;
	initial begin
		sig_state<=0;
	end
	always@(posedge sig_source)
		begin
			sig_state <=~sig_state;
		end
	always@(posedge clk_100kHz)
		begin	
			if(sig_state)
				sig_count <= sig_count+1;
			else
				sig_count<=0;
		end
	always@(negedge sig_state)
		begin
			sig_Hz_reg = N/sig_count;
		end
	always@(posedge clk_1Hz)
		begin
			sig_Hz = sig_Hz_reg/10;
		end
endmodule

binbcd14.v

`timescale 1ns / 1ps
module binbcd14(
	input wire [13:0]b,
	output reg [16:0]p
    );
	reg [32:0]z;
	integer i;
	always@(*)
		begin
			for(i=0;i<=32;i=i+1)
				z[i]=0;
			z[16:3]=b;
			repeat(11)
				begin
					if(z[17:14]>4)
						z[17:14]=z[17:14]+3;
					if(z[21:18]>4)
						z[21:18]=z[21:18]+3;
					if(z[25:22]>4)
						z[25:22]=z[25:22]+3;
					if(z[29:26]>4)
						z[29:26]=z[29:26]+3;
					z[32:1]=z[31:0];
				end
			p=z[30:14];
		end
	
endmodule

x7segbc.v

`timescale 1ns / 1ps

module x7segbc(
    input wire[15:0]x,
    input wire cclk,
    input wire clr,
    output reg[6:0]a_to_g,
    output reg[3:0]an
    );
    reg [1:0]s;
    reg[3:0]digit;
    wire [3:0]aen;
    assign aen[3]=x[15]|x[14]|x[13]|x[12];
    assign aen[2]=x[15]|x[14]|x[13]|x[12]|x[11]|x[10]|x[9]|x[8];
    assign aen[1]=x[15]|x[14]|x[13]|x[12]|x[11]|x[10]|x[9]|x[8]|x[7]|x[6]|x[5]|x[4];
    assign aen[0]=1;
    always@(*)
    case(s)
        0:digit=x[3:0];
        1:digit=x[7:4];
        2:digit=x[11:8];
        3:digit=x[15:12];
        default:digit=x[3:0];
    endcase
    
    always@(*)
    case(digit)
        0:a_to_g = 7'b1111110;
            1:a_to_g = 7'b0110000;
            2:a_to_g = 7'b1101101;
            3:a_to_g = 7'b1111001;
            4:a_to_g = 7'b0110011;
            5:a_to_g = 7'b1011011;
            6:a_to_g = 7'b1011111;
            7:a_to_g = 7'b1110000;
            8:a_to_g = 7'b1111111;
            9:a_to_g = 7'b1111011;
            'hA:a_to_g = 7'b1110111;
            'hB:a_to_g = 7'b0011111;
            'hC:a_to_g = 7'b1001110;
            'hD:a_to_g = 7'b0111101;
            'hE:a_to_g = 7'b1001111;
            'hF:a_to_g = 7'b1000111;
            default :a_to_g =7'b1111110;
    endcase
    always@(*)
    begin
        an=4'b0000;
        if(aen[s]==1)
            an[s]=1;
    end
    always@(posedge cclk or posedge clr)
    begin
        if(clr==1)
            s<=0;
        else
            s<=s+1;
    end
    
endmodule