verilog HDLBits刷题[Finite State Machines]“Lemmings1”---Lemmings1

1、题目The game Lemmings involves critters with fairly simple brains. So simple that we are going to model it using a finite state machine.In the Lemmings 2D world, Lemmings can be in one of two states: walking left or walking right. It will switch directions if it hits an obstacle. In particular, if a Lemming is bumped on the left, it will walk right. If its bumped on the right, it will walk left. If its bumped on both sides at the same time, it will still switch directions.Implement a Moore state machine with two states, two inputs, and one output that models this behaviour.See also: Lemmings2, Lemmings3, and Lemmings4.2、分析旅鼠游戏旅鼠只能向左或向右走撞到前进方向的障碍物就会改变方向。注意撞到非前进方向的障碍物不改变方向3、代码实现module top_module( input clk, input areset, // Freshly brainwashed Lemmings walk left. input bump_left, input bump_right, output walk_left, output walk_right); // parameter LEFT0, RIGHT1;//定义状态 reg state, next_state; //状态转换下一个状态 always (*) begin case(state) LEFT:begin if(bump_left) next_stateRIGHT; else next_stateLEFT; end RIGHT:begin if(bump_right) next_stateLEFT; else next_stateRIGHT; end endcase end //状态寄存器 always (posedge clk, posedge areset) begin if(areset) stateLEFT; else statenext_state; end //输出 assign walk_left (state LEFT); assign walk_right (state RIGHT); endmodule4、结果