module first_soft (clk, rst, led);//port
input clk, rst;
output [7:0] led;
reg [7:0] led;
reg [24:0] count;//计数器
reg [24:0] speed;//速度
reg [3:0] state;//状态,[3]=1:正转;[3]=0:翻转;{2,0}速度
always @(posedge clk or negedge rst)//自动变频流水灯
if (!rst)
begin
state<=4'd0;
led<=8'b00000001;
count<=25'd0;
speed<=25'd20000000;
end
else
begin
count<=count+1'b1;
if (count==speed)
begin
count<=25'd0;//计数器复位
if (state[3]==0)//转移发光二极管
begin
led<=led<<1'b1;
if (led==8'b01000000) state[3]<=1'b1;
end
else
begin
led<=led>>1'b1;
if (led==8'b00000010)
begin
case (state[2:0])
3'b000: begin speed<=25'd10000000; state[3:0]<=4'b0001; end
3'b001: begin speed<=25'd5000000; state[3:0]<=4'b0010; end
3'b010: begin speed<=25'd2500000; state[3:0]<=4'b0011; end
3'b011: begin speed<=25'd1200000; state[3:0]<=4'b0100; end
3'b100: begin speed<=25'd2500000; state[3:0]<=4'b0101; end
3'b101: begin speed<=25'd5000000; state[3:0]<=4'b0110; end
3'b110: begin speed<=25'd10000000; state[3:0]<=4'b0111; end
3'b111: begin speed<=25'd20000000; state[3:0]<=4'b0000; end
default: begin speed<=25'd20000000; state[3:0]<=4'b0000; end
endcase
end
end
end
end
endmodule
正转;[3]=0:翻转;{2,0}速度
你是想用LES实现呢还是用NIOS 2实现?
工作时钟频率多少?