4 files changed, 79 insertions, 0 deletions
diff --git a/src/synth/ghdlsynth_gates.h b/src/synth/ghdlsynth_gates.h
index 77c8c3a69..90ea283e8 100644
--- a/src/synth/ghdlsynth_gates.h
+++ b/src/synth/ghdlsynth_gates.h
@@ -56,6 +56,7 @@ enum Module_Id {
    Id_Output  = 50,
    Id_Ioutput = 51,
    Id_Port    = 52,
+   Id_Inout   = 53,
    Id_Dff   = 56,
    Id_Adff  = 57,
    Id_Idff  = 58,
diff --git a/testsuite/synth/issue1166/ent.vhdl b/testsuite/synth/issue1166/ent.vhdl
new file mode 100644
index 000000000..8f2f1b514
--- /dev/null
+++ b/testsuite/synth/issue1166/ent.vhdl
@@ -0,0 +1,24 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+entity ent is
+    port (
+        a      : inout std_logic;
+        enable : in std_logic;
+        d_in   : in std_logic;
+        d_out  : out std_logic
+    );
+end;
+
+architecture a of ent is
+begin
+    process(all)
+    begin
+        if enable then
+            a <= d_in;
+        else
+            a <= 'Z';
+        end if;
+    end process;
+    d_out <= a;
+end;
diff --git a/testsuite/synth/issue1166/tb_ent.vhdl b/testsuite/synth/issue1166/tb_ent.vhdl
new file mode 100644
index 000000000..016f6b685
--- /dev/null
+++ b/testsuite/synth/issue1166/tb_ent.vhdl
@@ -0,0 +1,45 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+entity tb_ent is
+end;
+
+architecture a of tb_ent is
+    signal a, enable, d_in, d_out : std_logic;
+begin
+    uut: entity work.ent
+        port map (
+            a => a,
+            enable => enable,
+            d_in => d_in,
+            d_out => d_out
+        );
+
+    process
+    begin
+        a <= '0';
+        enable <= '0';
+
+        wait for 10 ns;
+        assert d_out = '0';
+
+        a <= '1';
+
+        wait for 10 ns;
+        assert d_out = '1' severity failure;
+
+        enable <= '1';
+        a <= 'Z';
+        d_in <= '0';
+
+        wait for 10 ns;
+        assert a = '0' severity failure;
+
+        d_in <= '1';
+
+        wait for 10 ns;
+        assert a = '1' severity failure;
+
+        wait;
+    end process;
+end;
diff --git a/testsuite/synth/issue1166/testsuite.sh b/testsuite/synth/issue1166/testsuite.sh
new file mode 100755
index 000000000..047bcf9bb
--- /dev/null
+++ b/testsuite/synth/issue1166/testsuite.sh
@@ -0,0 +1,9 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+GHDL_STD_FLAGS=--std=08
+
+synth_tb ent
+
+echo "Test successful"