User`s manual

59 2’b10: begin
60 display_x <= x3;
61 display_y <= y3;
62 end
63 2’b11: begin
64 display_x <= x4;
65 display_y <= y4;
66 end
67 endcase
68 end
69
70 always @(posedge clk) begin
71 if (override && !(cur_state == OVERRIDE)) begin
72 cur_state <= OVERRIDE;
73 x1 <= x1_raw;
74 y1 <= y1_raw;
75 x2 <= x2_raw;
76 y2 <= y2_raw;
77 x3 <= x3_raw;
78 y3 <= y3_raw;
79 x4 <= x4_raw;
80 y4 <= y4_raw;
81 end
82 else if (override) begin
83 case (switch)
84 2’b00: begin
85 if (down) begin
86 y1 <= (y1 <= SCR_HEIGHT-YSPEED) ? (y1 + YSPEED) : y1;
87 end
88 else if (up) begin
89 y1 <= (y1 >= YSPEED) ? (y1 - YSPEED) : y1;
90 end
91 else if (left) begin
92 x1 <= (x1 >= XSPEED) ? (x1 - XSPEED) : x1;
93 end
94 else if (right) begin
95 x1 <= (x1 <= SCR_WIDTH-XSPEED) ? (x1 + XSPEED) : x1;
96 end
97 end
98 2’b01: begin
99 if (down) begin
100 y2 <= (y2 <= SCR_HEIGHT-YSPEED) ? (y2 + YSPEED) : y2;
101 end
102 else if (up) begin
103 y2 <= (y2 >= YSPEED) ? (y2 - YSPEED) : y2;
104 end
225