1 files changed, 31 insertions, 0 deletions
diff --git a/testsuite/synth/attr01/attr01.vhdl b/testsuite/synth/attr01/attr01.vhdl
new file mode 100644
index 000000000..1211efa24
--- /dev/null
+++ b/testsuite/synth/attr01/attr01.vhdl
@@ -0,0 +1,31 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+entity attr01 is
+  port (
+    rst : std_logic;
+    clk : std_logic;
+    cnt : out std_logic_vector (7 downto 0)
+    );
+end attr01;
+
+architecture behav of attr01 is
+  signal counter : std_logic_vector (7 downto 0);
+
+  attribute keep : boolean;
+  attribute keep of counter : signal is True;
+begin
+  process (clk)
+  begin
+    if rising_edge (clk) then
+      if rst = '1' then
+        counter <= (others => '0');
+      else
+        counter <= std_logic_vector (unsigned (counter) + 1);
+      end if;
+    end if;
+  end process;
+
+  cnt <= counter;
+end behav;