diff --git a/Keyboard Sample Code/KeyboardDecoder.v b/Keyboard Sample Code/KeyboardDecoder.v
index 3cde9d5..2f92e1e 100755
--- a/Keyboard Sample Code/KeyboardDecoder.v	
+++ b/Keyboard Sample Code/KeyboardDecoder.v	
@@ -17,9 +17,10 @@ module KeyboardDecoder(
     parameter [7:0] IS_EXTEND		= 8'hE0;
     parameter [7:0] IS_BREAK		= 8'hF0;
     
-    reg [9:0] key;		// key = {been_extend, been_break, key_in}
-    reg [1:0] state;
+    reg [9:0] key, next_key;		// key = {been_extend, been_break, key_in}
+    reg [1:0] state, next_state;
     reg been_ready, been_extend, been_break;
+    reg next_been_ready, next_been_extend, next_been_break;
     
     wire [7:0] key_in;
     wire is_extend;
@@ -56,56 +57,64 @@ module KeyboardDecoder(
     		been_break  <= 1'b0;
     		key <= 10'b0_0_0000_0000;
     	end else begin
-    		state <= state;
-			been_ready  <= been_ready;
-			been_extend <= (is_extend) ? 1'b1 : been_extend;
-			been_break  <= (is_break ) ? 1'b1 : been_break;
-			key <= key;
-    		case (state)
-    			INIT : begin
-    					if (key_in == IS_INIT) begin
-    						state <= WAIT_FOR_SIGNAL;
-    						been_ready  <= 1'b0;
-							been_extend <= 1'b0;
-							been_break  <= 1'b0;
-							key <= 10'b0_0_0000_0000;
-    					end else begin
-    						state <= INIT;
-    					end
-    				end
-    			WAIT_FOR_SIGNAL : begin
-    					if (valid == 0) begin
-    						state <= WAIT_FOR_SIGNAL;
-    						been_ready <= 1'b0;
-    					end else begin
-    						state <= GET_SIGNAL_DOWN;
-    					end
-    				end
-    			GET_SIGNAL_DOWN : begin
-						state <= WAIT_RELEASE;
-						key <= {been_extend, been_break, key_in};
-						been_ready  <= 1'b1;
-    				end
-    			WAIT_RELEASE : begin
-    					if (valid == 1) begin
-    						state <= WAIT_RELEASE;
-    					end else begin
-    						state <= WAIT_FOR_SIGNAL;
-    						been_extend <= 1'b0;
-    						been_break  <= 1'b0;
-    					end
-    				end
-    			default : begin
-    					state <= INIT;
-						been_ready  <= 1'b0;
-						been_extend <= 1'b0;
-						been_break  <= 1'b0;
-						key <= 10'b0_0_0000_0000;
-    				end
-    		endcase
+    		state <= next_state;
+			been_ready  <= next_been_ready;
+			been_extend <= next_been_extend;
+			been_break  <= next_been_break;
+			key <= next_key;
     	end
     end
     
+	always @ (*) begin
+		case (state)
+			INIT:            next_state = (key_in == IS_INIT) ? WAIT_FOR_SIGNAL : INIT;
+			WAIT_FOR_SIGNAL: next_state = (valid == 1'b0) ? WAIT_FOR_SIGNAL : GET_SIGNAL_DOWN;
+			GET_SIGNAL_DOWN: next_state = WAIT_RELEASE;
+			WAIT_RELEASE:    next_state = (valid == 1'b1) ? WAIT_RELEASE : WAIT_FOR_SIGNAL;
+			default:         next_state = INIT;
+		endcase
+	end
+	always @ (*) begin
+		next_been_ready = been_ready;
+		case (state)
+			INIT:            next_been_ready = (key_in == IS_INIT) ? 1'b0 : next_been_ready;
+			WAIT_FOR_SIGNAL: next_been_ready = (valid == 1'b0) ? 1'b0 : next_been_ready;
+			GET_SIGNAL_DOWN: next_been_ready = 1'b1;
+			WAIT_RELEASE:    next_been_ready = next_been_ready;
+			default:         next_been_ready = 1'b0;
+		endcase
+	end
+	always @ (*) begin
+		next_been_extend = (is_extend) ? 1'b1 : been_extend;
+		case (state)
+			INIT:            next_been_extend = (key_in == IS_INIT) ? 1'b0 : next_been_extend;
+			WAIT_FOR_SIGNAL: next_been_extend = next_been_extend;
+			GET_SIGNAL_DOWN: next_been_extend = next_been_extend;
+			WAIT_RELEASE:    next_been_extend = (valid == 1'b1) ? next_been_extend : 1'b0;
+			default:         next_been_extend = 1'b0;
+		endcase
+	end
+	always @ (*) begin
+		next_been_break = (is_break) ? 1'b1 : been_break;
+		case (state)
+			INIT:            next_been_break = (key_in == IS_INIT) ? 1'b0 : next_been_break;
+			WAIT_FOR_SIGNAL: next_been_break = next_been_break;
+			GET_SIGNAL_DOWN: next_been_break = next_been_break;
+			WAIT_RELEASE:    next_been_break = (valid == 1'b1) ? next_been_break : 1'b0;
+			default:         next_been_break = 1'b0;
+		endcase
+	end
+	always @ (*) begin
+		next_key = key;
+		case (state)
+			INIT:            next_key = (key_in == IS_INIT) ? 10'b0_0_0000_0000 : next_key;
+			WAIT_FOR_SIGNAL: next_key = next_key;
+			GET_SIGNAL_DOWN: next_key = {been_extend, been_break, key_in};
+			WAIT_RELEASE:    next_key = next_key;
+			default:         next_key = 10'b0_0_0000_0000;
+		endcase
+	end
+
     always @ (posedge clk, posedge rst) begin
     	if (rst) begin
     		key_valid <= 1'b0;