diff --git a/lib/filter/src/fir_parallel.vhd b/lib/filter/src/fir_parallel.vhd
index 2561848..75fd554 100644
--- a/lib/filter/src/fir_parallel.vhd
+++ b/lib/filter/src/fir_parallel.vhd
@@ -109,6 +109,7 @@ architecture Behavioral of fir_parallel is
 	SIGNAL x    	   : stages_array_t(0 to ntaps-2);
 	SIGNAL y           : stages_array_t(0 to ntaps-2);
 	SIGNAL h           : coeff_array_t(0 to ntaps-1);
+	SIGNAL vld		   : unsigned(0 to ntaps-2);
 	
 	-------------------------------------------------------------------------------
 begin
@@ -144,7 +145,7 @@ begin
 			x_in		=> d_in,
 			y_in		=> zero_in,
 			h_in		=> h(ntaps-1),
-			out_valid	=> out_valid,
+			out_valid	=> vld(0),
 			x_out		=> x(0),
 			y_out		=> y(0),
 			y_out_clr	=> '0'
@@ -171,11 +172,11 @@ begin
 		(
 			srst		=> srst,
 			clk			=> clk,
-			in_valid	=> in_valid,
+			in_valid	=> vld(i-1),
 			x_in		=> x(i-1),
 			y_in		=> y(i-1),
 			h_in		=> h(ntaps-i-1),
-			out_valid	=> open,
+			out_valid	=> vld(i),
 			x_out		=> x(i),
 			y_out		=> y(i),
 			y_out_clr	=> '0'
@@ -201,11 +202,11 @@ begin
 		(
 			srst		=> srst,
 			clk			=> clk,
-			in_valid	=> in_valid,
+			in_valid	=> vld(ntaps-2),
 			x_in		=> x(ntaps-2),
 			y_in		=> y(ntaps-2),
 			h_in		=> h(0),
-			out_valid	=> open,
+			out_valid	=> out_valid,
 			x_out		=> x_out,
 			y_out		=> d_out,
 			y_out_clr	=> '0'
diff --git a/lib/filter/src/tb_fir_parallel.vhd b/lib/filter/src/tb_fir_parallel.vhd
index e1ff939..975b01d 100644
--- a/lib/filter/src/tb_fir_parallel.vhd
+++ b/lib/filter/src/tb_fir_parallel.vhd
@@ -184,7 +184,7 @@ BEGIN
 
 	BEGIN
 		if rising_edge(clk) and fileout_enable = '1' and out_valid = '1' then
-			so := to_integer(y_out);
+			so := to_integer(to_signed(y_out));
 			write(fo, so);
 		end if;