Add new tests for ice40 architecture

tests/ice40/mux_tb.v

@@ -0,0 +1,43 @@
+module testbench;
+    reg clk;
+
+    initial begin
+        // $dumpfile("testbench.vcd");
+        // $dumpvars(0, testbench);
+
+        #5 clk = 0;
+        repeat (10000) begin
+            #5 clk = 1;
+            #5 clk = 0;
+        end
+
+        $display("OKAY");    
+    end
+   
+    
+    reg [15:0] D = 1;
+    reg [3:0] S = 0;
+    wire M2,M4,M8,M16;
+
+    top uut (
+        .S (S ),
+        .D (D ),
+        .M2 (M2 ),
+        .M4 (M4 ),
+        .M8 (M8 ),
+        .M16 (M16 )
+    );
+    
+    always @(posedge clk) begin
+    //#3;
+	D <= {D[14:0],D[15]};
+    //D <= D <<< 1;
+    S <= S + 1;
+    end
+	
+	assert_tri m2_test(.en(clk), .A(D[0]|D[1]), .B(M2));
+	assert_tri m4_test(.en(clk), .A(D[0]|D[1]|D[2]|D[3]), .B(M4));
+	assert_tri m8_test(.en(clk), .A(!S[3]), .B(M8));
+	assert_tri m16_test(.en(clk), .A(1'b1), .B(M16));
+  
+endmodule