重学Veriliog(2)——高级编程语句

casez (encoder)
    4‘b1???: high_lvl = 3;
    4‘b01??: high_lvl = 2;
    4‘b001?: high_lvl = 1;
    4‘b0001: high_lvl = 0;
    default : high_lvl = 0;
endcase

casez (encoder)
    4‘b1xxx: high_lvl = 3;
    4‘b01xx: high_lvl = 2;
    4‘b001x: high_lvl = 1;
    4‘b0001: high_lvl = 0;
    default : high_lvl = 0;
endcase

initial
begin
clk = 0;
forver #25 clk = ~clk;
end

if (rotate == 1)
    repeat(8)
        begin
            tmp = data[15];
            data = {data << 1,tmp};
        end

1 initial
2 begin
3     count = 0;
4     while (count < 101)
5     begin
6         $ display ("Count = %d" , count);
7         count = count + 1;
8     end
9 end

 1 integer i;
 2 always @(inp or cnt)
 3 begin
 4     result[7:4] = 0;
 5     result[3:0] = inp;
 6     if (cnt == 1)
 7     begin
 8     for (i = 4; i  <= 7; i=i+1)
 9         begin
10             result[i]=result[i - 4];
11         end
12     result[3:0] = 0;
13     end
14 end