Added sign extension for 2 bits into 9 bits, just to test first

lab2CA.srcs/sources_1/new/BasicModules.v

@@ -961,6 +961,14 @@ module shift_right_arithmetic_tb();
     end
 endmodule
 
+module sign_extend_2bit(
+    input wire [1:0] A,
+    output wire [8:0] B);
+
+    B = {{7{A[1]}},A};
+
+endmodule
+
 module sub_9bit(
     input wire [8:0] A,
     input wire [8:0] B,