网站建设php培训,网站都有什么费用,苏州市建设局投诉网站,很简单的网站Lemmings又多了一种状态#xff1a;dig#xff0c;我按照上一篇文章里大神的思路又多加了两种状态#xff1a;LEFT_DIGGING与RIGHT_DIGGING#xff0c;写出了如下的代码#xff1a;
module top_module(input clk,input areset, // Freshly brainwashed Lemmings walk …Lemmings又多了一种状态dig我按照上一篇文章里大神的思路又多加了两种状态LEFT_DIGGING与RIGHT_DIGGING写出了如下的代码
module top_module(input clk,input areset, // Freshly brainwashed Lemmings walk left.input bump_left,input bump_right,input ground,input dig,output walk_left,output walk_right,output aaah,output digging ); parameter LEFT4b000001, RIGHT4b000010, LEFT_FALLING4b000100, RIGHT_FALLING4b001000, LEFT_DIGGING4b010000, RIGHT_DIGGING4b100000;reg [3:0] state,next_state;always(*)begincase(state)LEFT: next_state ground?(dig?LEFT_DIGGING:(bump_left?RIGHT:LEFT)):LEFT_FALLING; RIGHT: next_state ground?(dig?RIGHT_DIGGING:(bump_right?LEFT:RIGHT)):RIGHT_FALLING; LEFT_FALLING: next_state ground?LEFT:LEFT_FALLING;RIGHT_FALLING: next_state ground?RIGHT:RIGHT_FALLING;LEFT_DIGGING: next_state ground?(dig?LEFT_DIGGING:(bump_left?RIGHT:LEFT)):LEFT_FALLING;RIGHT_DIGGING: next_state ground?(dig?RIGHT_DIGGING:(bump_right?LEFT:RIGHT)):RIGHT_FALLING;default: next_state LEFT;endcase endalways(posedge clk or posedge areset)beginif(areset)state LEFT;elsestate next_state;endassign walk_left (state LEFT);assign walk_right (state RIGHT);assign aaah (state LEFT_FALLING || state RIGHT_FALLING);assign digging (state RIGHT_DIGGING || state LEFT_DIGGING); endmodule跑出来有错误检查了时序图发现这道题目跟我理解的不一致我以为input中的dig一直为1时lemming才一直挖地原来是只要dig输入过1lemming会一直挖地直到尽头。然后我改掉了LEFT_DIGGING和RIGHT_DIGGING的状态转换的条件得到如下的代码
module top_module(input clk,input areset, // Freshly brainwashed Lemmings walk left.input bump_left,input bump_right,input ground,input dig,output walk_left,output walk_right,output aaah,output digging ); parameter LEFT4b000001, RIGHT4b000010, LEFT_FALLING4b000100, RIGHT_FALLING4b001000, LEFT_DIGGING4b010000, RIGHT_DIGGING4b100000;reg [3:0] state,next_state;always(*)begincase(state)LEFT: next_state ground?(dig?LEFT_DIGGING:(bump_left?RIGHT:LEFT)):LEFT_FALLING; RIGHT: next_state ground?(dig?RIGHT_DIGGING:(bump_right?LEFT:RIGHT)):RIGHT_FALLING; LEFT_FALLING: next_state ground?LEFT:LEFT_FALLING;RIGHT_FALLING: next_state ground?RIGHT:RIGHT_FALLING;LEFT_DIGGING: next_state ground?LEFT_DIGGING:LEFT_FALLING;RIGHT_DIGGING: next_state ground?RIGHT_DIGGING:RIGHT_FALLING;default: next_state LEFT;endcase endalways(posedge clk or posedge areset)beginif(areset)state LEFT;elsestate next_state;endassign walk_left (state LEFT);assign walk_right (state RIGHT);assign aaah (state LEFT_FALLING || state RIGHT_FALLING);assign digging (state RIGHT_DIGGING || state LEFT_DIGGING); endmodule仍然有错误是在RIGHT状态下的bump_right和dig两个输入同时为1的时候出了问题lemming一开始的反应去挖地了没有问题但是挖完地以后改变了方向变成了LEFT_DIGGING而参考答案中没有改变方向是RIGHT_DIGGING。
然后检查到这里我发现一个大问题我的parameter和和state的长度不对那时序图怎么跑到1940才发现错误呢把parameter和state的长度改正之后终于success了。
按照我错误的写法LEFT_DIGGING和RIGHT_DIGGING应该会被视为一种状态所以只会执行case中排在前面的LEFT_DIGGING的状态转换所以不会影响LEFT_DIGGING只会影响RIGHT_DIGGING。因此导致了上面的错误。所以case里的条件是有顺序的排在前面的匹配了后面的就不检查了为了验证这个猜测我把case里LEFT_DIGGING和RIGHT_DIGGING交换了位置把RIGHT_DIGGING放在了前面果然影响到了LEFT_DIGGING。
