連載
よろしいならばダイナミック点灯だ――FPGAでLEDをダイナミックにLチカさせる：MAX 10 FPGAで学ぶFPGA開発入門（5）（2/6 ページ）
単純なLチカならばFPGAでもそう難しくない。ただ、ダイナミック点灯やそれに伴うソースの最適化については“ならでは”のポイントが散見される。今回も連載で利用している「MAX 10 FPGA 評価キット」の読者プレゼントをご用意。
module top(
//Clock from oscillator
input Clock,
//Arduino I/Os
inout Arduino_IO5,
inout Arduino_IO6,
inout Arduino_IO7,
inout Arduino_IO8,
inout Arduino_IO9,
inout Arduino_IO10,
inout Arduino_IO11,
inout Arduino_IO12,
inout Arduino_IO13
);
reg[18:0] div_cntr1;
reg[9:0] div_cntr2;
reg[3:0] dec_cntr;
reg[3:0] pos_cntr;
reg[6:0] seg_cntr;
reg[7:0] disp_cntr;
reg Hi;
initial begin
div_cntr1 = 0;
div_cntr2 = 0;
dec_cntr = 0;
seg_cntr = 0;
pos_cntr = 0;
Hi = 1;
end
always@(posedge Clock) begin
div_cntr1 <= div_cntr1 + 1;
if (div_cntr1 == 50000) begin
div_cntr1 <= 0;
div_cntr2 <= div_cntr2 + 1;
if (div_cntr2 == 1000) begin
div_cntr2 <= 0;
case (dec_cntr)
0 : seg_cntr <= 7'b0000100; // 1111011
1 : seg_cntr <= 7'b1100111; // 0011000
2 : seg_cntr <= 7'b1001000; // 0110111
3 : seg_cntr <= 7'b1000001; // 0111110
4 : seg_cntr <= 7'b0100011; // 1011100
5 : seg_cntr <= 7'b0010001; // 1101110
6 : seg_cntr <= 7'b0010000; // 1101111
7 : seg_cntr <= 7'b1000111; // 0111000
8 : seg_cntr <= 7'b0000000; // 1111111
9 : seg_cntr <= 7'b0000001; // 1111110
default : seg_cntr <= 7'b1111111; // 0000000
endcase
dec_cntr <= dec_cntr + 1;
if (dec_cntr == 9) begin
dec_cntr <= 0;
end
end
else begin
pos_cntr <= pos_cntr + 1;
case (pos_cntr)
0 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= seg_cntr[6];
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
1 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= seg_cntr[5] ;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
2 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= seg_cntr[4] ;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
3 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= seg_cntr[3] ;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
4 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= seg_cntr[2] ;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
5 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= seg_cntr[1] ;
disp_cntr[0] <= 1;
end
6 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= seg_cntr[0] ;
end
6 : begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= seg_cntr[0] ;
end
7 : begin
disp_cntr[7] <= dec_cntr[0] ;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= seg_cntr[0] ;
end
default: begin
disp_cntr[7] <= 1;
disp_cntr[6] <= 1;
disp_cntr[5] <= 1;
disp_cntr[4] <= 1;
disp_cntr[3] <= 1;
disp_cntr[2] <= 1;
disp_cntr[1] <= 1;
disp_cntr[0] <= 1;
end
endcase
end
end
end
assign Arduino_IO5 = Hi ;
assign Arduino_IO6 = disp_cntr[6] ;
assign Arduino_IO7 = disp_cntr[5] ;
assign Arduino_IO8 = disp_cntr[4] ;
assign Arduino_IO9 = disp_cntr[7] ;
assign Arduino_IO10 = disp_cntr[3] ;
assign Arduino_IO11 = disp_cntr[2] ;
assign Arduino_IO12 = disp_cntr[1] ;
assign Arduino_IO13 = disp_cntr[0] ;
endmodule
List1
Copyright © ITmedia, Inc. All Rights Reserved.