rtl: add sources for ethernet udp stack

rtl/ethernet-udp/src/eth/reset.v

@@ -0,0 +1,20 @@
+
+module reset(
+	input clk,
+	input key1,
+	output rst_n
+);
+reg[27:0] cnt = 28'd0;
+reg rst_n_reg;
+assign rst_n = rst_n_reg;
+always@(posedge clk)
+   if(key1==1'b0)
+        cnt <= 0;
+    else
+    	if(cnt != 28'h3ffffff)
+	    	cnt <= cnt + 1'd1;
+	    else
+		    cnt <= cnt;
+always@(posedge clk)
+	rst_n_reg <= (cnt == 28'h3ffffff);
+endmodule