Initial commit

Labs/09. Peripheral units/PS2Receiver.v

@@ -0,0 +1,95 @@
+`timescale 1ns / 1ps
+
+module PS2Receiver(
+    input clk,
+    input kclk,
+    input kdata,
+    output reg [15:0] keycodeout,
+    output keycode_valid
+    );
+
+    reg flag;
+    reg [3:0] flag_shift;
+    wire kclkf, kdataf;
+    reg [3:0]cnt;
+
+    assign keycode_valid = flag_shift[0] && !flag_shift[2];
+
+    initial begin //for tb
+      cnt = 0;
+      keycodeout = 0;
+      flag_shift = 0;
+      flag = 0;
+    end
+
+debouncer debounce(
+    .clk(clk),
+    .I0(kclk),
+    .I1(kdata),
+    .O0(kclkf),
+    .O1(kdataf)
+);
+always@(posedge clk) begin
+    flag_shift <= (flag_shift << 1) + flag;
+end
+
+always@(negedge(kclkf))begin
+    case(cnt)
+    0:if(keycodeout != 16'hE000)keycodeout <= 0;//Start bit
+    1:keycodeout[0]<=kdataf;
+    2:keycodeout[1]<=kdataf;
+    3:keycodeout[2]<=kdataf;
+    4:keycodeout[3]<=kdataf;
+    5:keycodeout[4]<=kdataf;
+    6:keycodeout[5]<=kdataf;
+    7:keycodeout[6]<=kdataf;
+    8:keycodeout[7]<=kdataf;
+    //TODO ADD PARITY CHECK
+    9:begin
+        flag<=1'b1;
+        if(keycodeout[7:0] == 8'hE0) begin
+            keycodeout <= {keycodeout[7:0], 8'd0};
+        end
+    end
+    10:flag<=1'b0;
+    default: cnt <= 0;
+    endcase
+        if(cnt<=9) cnt<=cnt+1;
+        else if(cnt==10) cnt<=0;
+end
+
+endmodule
+
+
+module debouncer(
+    input clk,
+    input I0,
+    input I1,
+    output reg O0,
+    output reg O1
+    );
+    
+    reg [4:0]cnt0, cnt1;
+    reg Iv0=0,Iv1=0;
+    reg out0, out1;
+    
+always@(posedge(clk))begin
+    if (I0==Iv0)begin
+        if (cnt0==19)O0<=I0;
+        else cnt0<=cnt0+1;
+      end
+    else begin
+        cnt0<="00000";
+        Iv0<=I0;
+    end
+    if (I1==Iv1)begin
+            if (cnt1==19)O1<=I1;
+            else cnt1<=cnt1+1;
+          end
+        else begin
+            cnt1<="00000";
+            Iv1<=I1;
+        end
+    end
+    
+endmodule