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diff --git a/tests/simple/loops.v b/tests/simple/loops.v
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+
+// a simple test case extracted from systemcaes (as included in iwls2005)
+// this design has latches (or logic loops) for the two temp variables.
+// this latches (or logic loops) must be removed in the final synthesis results
+
+module aes(
+	// inputs
+	input [3:0] addroundkey_data_i,
+	input [3:0] addroundkey_data_reg,
+	input [3:0] addroundkey_round,
+	input [3:0] key_i,
+	input [3:0] keysched_new_key_o,
+	input [3:0] round,
+	input addroundkey_start_i,
+	input keysched_ready_o,
+
+	// outputs
+	output reg [3:0] keysched_last_key_i,
+	output reg [3:0] keysched_round_i,
+	output reg [3:0] next_addroundkey_data_reg,
+	output reg [3:0] next_addroundkey_round,
+	output reg [3:0] round_data_var,
+	output reg keysched_start_i,
+	output reg next_addroundkey_ready_o
+);
+
+// temp variables
+reg [3:0] data_var;
+reg [3:0] round_key_var;
+
+always @*
+begin
+	keysched_start_i = 0;
+	keysched_round_i = addroundkey_round;
+	round_data_var = addroundkey_data_reg;
+	next_addroundkey_data_reg = addroundkey_data_reg;
+	next_addroundkey_ready_o = 0;
+	next_addroundkey_round = addroundkey_round;
+
+	if (addroundkey_round == 1 || addroundkey_round == 0)
+		keysched_last_key_i = key_i;
+	else
+		keysched_last_key_i = keysched_new_key_o;
+	
+	if (round == 0 && addroundkey_start_i)
+	begin
+		data_var = addroundkey_data_i;	
+		round_key_var = key_i;
+		round_data_var = round_key_var ^ data_var;
+		next_addroundkey_data_reg = round_data_var;
+		next_addroundkey_ready_o = 1;
+	end
+	else if (addroundkey_start_i && round != 0)
+	begin
+		keysched_last_key_i = key_i;
+		keysched_start_i = 1;
+		keysched_round_i = 1;
+		next_addroundkey_round = 1;
+	end
+	else if (addroundkey_round != round && keysched_ready_o)
+	begin
+		next_addroundkey_round = addroundkey_round + 1;
+		keysched_last_key_i = keysched_new_key_o;
+		keysched_start_i = 1;
+		keysched_round_i = addroundkey_round + 1;
+	end
+	else if (addroundkey_round == round && keysched_ready_o)
+	begin
+		data_var = addroundkey_data_i;	
+		round_key_var = keysched_new_key_o;
+		round_data_var = round_key_var ^ data_var;
+		next_addroundkey_data_reg = round_data_var;
+		next_addroundkey_ready_o = 1;
+		next_addroundkey_round = 0;
+	end
+end
+
+endmodule
+