verilog之计数器0~9999——数码管显示
verilog的语法是比较好理解的，当然是相对于VHDL楼，废话不说，直接上代码：
/* file name : led4_cnt.v(for 4-bit) author : LiMing date : 2012/06/07 description : Light one bit 7-segment and display 0 1 2 ... e f. in every constant time fpga : Cyclone III EP3C16F484C6 board : DE0 (ter-asic Ltd.) successful!!! in DE0 board unsigned char code[]= { 0x40, 0x79, 0x24, 0x30, 0x19, 0x12, 0x02, 0x78, 0x00, 0x10, 0x08, 0x03, 0x46, 0x21, 0x06, 0x0e }; */ module led4_cnt(clk_50, sega7, segb7, segc7, segd7); input clk_50; output [6:0] sega7; reg [6:0] sega7; output [6:0] segb7; reg [6:0] segb7; output [6:0] segc7; reg [6:0] segc7; output [6:0] segd7; reg [6:0] segd7; reg clk1k; //frequency division //1khz reg clk1hz; //second clk signal reg [14:0] count_1khz; //count for frequency division //reg [24:0] count_1hz; reg [8:0] count_1hz; reg [3:0] num_ge; reg [3:0] num_shi; reg [3:0] num_bai; reg [3:0] num_qian; parameter time_limited_1khz = 15'd25_000; //parameter time_limited_1hz = 25'd25_000_000; parameter time_limited_1hz = 9'd500; initial begin sega7 <= 7'b100_0000; segb7 <= 7'b111_1001; segc7 <= 7'b010_0100; segd7 <= 7'b011_0000; num_ge = 4'd0; num_shi = 4'd0; num_bai = 4'd0; num_qian = 4'd0; clk1k = 1'd0; clk1hz = 1'd0; end //分频电时钟模块路 generate 1khz always@(posedge clk_50)//50M-1k,50M/1k/2//分频,50Mhz~1khz,占空比50% begin if(count_1khz == time_limited_1khz) begin clk1k <= ~clk1k; count_1khz <= 0; end else count_1khz <= count_1khz + 1'd1; end //分频电时钟模块路 generate 1hz /* always@(posedge clk_50)//50M-1hHz,50M/1Hz/2//分频,50Mhz~1khz,占空比50% begin if(count_1hz == time_limited_1hz) begin clk1hz <= ~clk1hz; count_1hz <= 0; end else count_1hz <= count_1hz + 1'd1; end */ //分频电时钟模块路 generate 1hz always@(posedge clk1k)//1kHz~1Hz,占空比50% begin if(count_1hz == time_limited_1hz) begin clk1hz <= ~clk1hz; count_1hz <= 0; end else count_1hz <= count_1hz + 1'd1; end /* if(count == time_limited_1hz) begin clk1hz <= ~clk1hz; count <= 0; end else count <= count + 1'b1; */ // always @(posedge clk1hz) begin //if(num_ge==4'd10 && num_shi<4'd10) if(num_ge==4'd9 && num_shi<4'd10 && num_bai<4'd10 && num_qian<4'd10) begin num_ge <= 4'd0; num_shi <= num_shi + 4'd1; if(num_shi == 4'd9 && num_bai<4'd10 && num_qian<4'd10) begin num_shi <= 4'd0; num_bai <= num_bai + 4'd1; end if(num_bai == 4'd9 && num_qian<4'd10) begin num_bai <= 4'd0; num_qian <= num_qian + 4'd1; end end /* //else if(num_shi==4'd10 && num_bai<4'd10) else if(num_shi==4'd10) begin num_shi <= 4'd0; num_bai <= num_bai + 4'd1; end //else if(num_bai==4'd10 && num_qian<4'd10) else if(num_bai==4'd10) begin num_bai <= 4'd0; num_qian <= num_qian + 4'd1; end */ else if(num_qian==4'd10 && num_bai==4'd9 && num_shi==4'd9 && num_ge==4'd9) begin num_ge <= 4'd0; num_shi <= 4'd0; num_bai <= 4'd0; num_qian <= 4'd0; end else begin num_ge <= num_ge + 4'd1; end end /*always @(posedge clk_50) begin if(count < time_limited) begin count <= count + 1'b1; flag = 1'b0; end else begin count = 24'd0; flag = 1'b1; end end always @(posedge flag) begin if (num < 4'hf) num <= num + 1'b1; else num <= 4'd0; end */ //display ge wei always @(num_ge) begin case(num_ge) 4'h0: sega7 = 7'b100_0000; 4'h1: sega7 = 7'b111_1001; // ---a---- 0x40 4'h2: sega7 = 7'b010_0100; // | | 0x70 4'h3: sega7 = 7'b011_0000; // f b 0x24 4'h4: sega7 = 7'b001_1001; // | | 0x30 4'h5: sega7 = 7'b001_0010; // ---g---- 0x19 4'h6: sega7 = 7'b000_0010; // | | 0x12 4'h7: sega7 = 7'b111_1000; // e c 0x02 4'h8: sega7 = 7'b000_0000; // | | 0x78 4'h9: sega7 = 7'b001_0000; // ---d----. 0x00 /*4'ha: sega7 = 8'b0001_0000; // 0x10 4'hb: sega7 = 8'b0000_1000; // 0x08 4'hc: sega7 = 8'b0000_0011; // 0x03 4'hd: sega7 = 8'b0100_0110; // 0x46 4'he: sega7 = 8'b0010_0001; // 0x21 4'hf: sega7 = 8'b0000_0110; // 0x06*/ default: sega7 = 7'b100_0000; // 0x40 endcase end //display shi wei always @(num_shi) begin case(num_shi) 4'h0: segb7 = 7'b100_0000; 4'h1: segb7 = 7'b111_1001; // ---a---- 0x40 4'h2: segb7 = 7'b010_0100; // | | 0x70 4'h3: segb7 = 7'b011_0000; // f b 0x24 4'h4: segb7 = 7'b001_1001; // | | 0x30 4'h5: segb7 = 7'b001_0010; // ---g---- 0x19 4'h6: segb7 = 7'b000_0010; // | | 0x12 4'h7: segb7 = 7'b111_1000; // e c 0x02 4'h8: segb7 = 7'b000_0000; // | | 0x78 4'h9: segb7 = 7'b001_0000; // ---d----. 0x00 default: segb7 = 7'b100_0000; // 0x40 endcase end //display bai wei always @(num_bai) begin case(num_bai) 4'h0: segc7 = 7'b100_0000; 4'h1: segc7 = 7'b111_1001; // ---a---- 0x40 4'h2: segc7 = 7'b010_0100; // | | 0x70 4'h3: segc7 = 7'b011_0000; // f b 0x24 4'h4: segc7 = 7'b001_1001; // | | 0x30 4'h5: segc7 = 7'b001_0010; // ---g---- 0x19 4'h6: segc7 = 7'b000_0010; // | | 0x12 4'h7: segc7 = 7'b111_1000; // e c 0x02 4'h8: segc7 = 7'b000_0000; // | | 0x78 4'h9: segc7 = 7'b001_0000; // ---d----. 0x00 default: segc7 = 7'b100_0000; // 0x40 endcase end //display qian wei always @(num_qian) begin case(num_qian) 4'h0: segd7 = 7'b100_0000; 4'h1: segd7 = 7'b111_1001; // ---a---- 0x40 4'h2: segd7 = 7'b010_0100; // | | 0x70 4'h3: segd7 = 7'b011_0000; // f b 0x24 4'h4: segd7 = 7'b001_1001; // | | 0x30 4'h5: segd7 = 7'b001_0010; // ---g---- 0x19 4'h6: segd7 = 7'b000_0010; // | | 0x12 4'h7: segd7 = 7'b111_1000; // e c 0x02 4'h8: segd7 = 7'b000_0000; // | | 0x78 4'h9: segd7 = 7'b001_0000; // ---d----. 0x00 default: segd7 = 7'b100_0000; // 0x40 endcase end endmodule
有一点要注意的就是，几个always语句是并行执行的，和C语言有区别，当然这个代码也只是个Demo板，还有待于优化和模块化管理，硬件运行的环境是DE0开发板，如代码的开头处所说，软件环境是Quartus II web-edition 8.1,呵呵虽说是网络版，但是还是可以用滴！不过在引脚分配的时候，有点不一样，于是我用了Tcl脚本来实现之：
set_location_assignment PIN_E11 -to sega7[0] set_location_assignment PIN_F11 -to sega7[1] set_location_assignment PIN_H12 -to sega7[2] set_location_assignment PIN_H13 -to sega7[3] set_location_assignment PIN_G12 -to sega7[4] set_location_assignment PIN_F12 -to sega7[5] set_location_assignment PIN_F13 -to sega7[6] #set_location_assignment PIN_D13 -to sega7[7] set_location_assignment PIN_A13 -to segb7[0] set_location_assignment PIN_B13 -to segb7[1] set_location_assignment PIN_C13 -to segb7[2] set_location_assignment PIN_A14 -to segb7[3] set_location_assignment PIN_B14 -to segb7[4] set_location_assignment PIN_E14 -to segb7[5] set_location_assignment PIN_A15 -to segb7[6] #set_location_assignment PIN_B15 -to segb7[7] set_location_assignment PIN_D15 -to segc7[0] set_location_assignment PIN_A16 -to segc7[1] set_location_assignment PIN_B16 -to segc7[2] set_location_assignment PIN_E15 -to segc7[3] set_location_assignment PIN_A17 -to segc7[4] set_location_assignment PIN_B17 -to segc7[5] set_location_assignment PIN_F14 -to segc7[6] #set_location_assignment PIN_A18 -to segc7[7] set_location_assignment PIN_B18 -to segd7[0] set_location_assignment PIN_F15 -to segd7[1] set_location_assignment PIN_A19 -to segd7[2] set_location_assignment PIN_B19 -to segd7[3] set_location_assignment PIN_C19 -to segd7[4] set_location_assignment PIN_D19 -to segd7[5] set_location_assignment PIN_G15 -to segd7[6] #set_location_assignment PIN_G16 -to segd7[7] set_location_assignment PIN_G21 -to clk_50
点击进行如下步骤，当前激活为verilog文件：
这样就会产生一个当前verilog文件的针对原理图文件的symbol。
新建一个原理图文件，插入所需的文件，
然后运行Tcl文件，tools->Tcl scripts：
最后下载，结果如下：
哈哈，请各位看官点评哦！
