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author | Tristan Gingold <tgingold@free.fr> | 2020-02-17 18:37:09 +0100 |
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committer | Tristan Gingold <tgingold@free.fr> | 2020-02-17 18:37:09 +0100 |
commit | 5b9ccf680b139a94bd164bd0fba57b1e4a5535d3 (patch) | |
tree | 8acf2ea3071bbd873c358f5a51752d6d229de358 /src/synth/netlists-inference.adb | |
parent | 4284956d63b11db7e6b003f9c5ca81ea6eb234ff (diff) | |
download | ghdl-5b9ccf680b139a94bd164bd0fba57b1e4a5535d3.tar.gz ghdl-5b9ccf680b139a94bd164bd0fba57b1e4a5535d3.tar.bz2 ghdl-5b9ccf680b139a94bd164bd0fba57b1e4a5535d3.zip |
synth: add mdff.
Diffstat (limited to 'src/synth/netlists-inference.adb')
-rw-r--r-- | src/synth/netlists-inference.adb | 54 |
1 files changed, 44 insertions, 10 deletions
diff --git a/src/synth/netlists-inference.adb b/src/synth/netlists-inference.adb index 9f82e7207..8786d42eb 100644 --- a/src/synth/netlists-inference.adb +++ b/src/synth/netlists-inference.adb @@ -328,6 +328,7 @@ package body Netlists.Inference is Stmt : Synth.Source.Syn_Src) return Net is O : constant Net := Get_Output (Last_Mux, 0); + Mux_Loc : constant Location_Type := Get_Location (Last_Mux); Data : Net; Res : Net; Sig : Instance; @@ -335,6 +336,7 @@ package body Netlists.Inference is Rst : Net; Rst_Val : Net; Enable : Net; + Els : Net; begin -- Create and return the DFF. @@ -344,12 +346,31 @@ package body Netlists.Inference is Sel : constant Input := Get_Mux2_Sel (Last_Mux); I0 : constant Input := Get_Mux2_I0 (Last_Mux); I1 : constant Input := Get_Mux2_I1 (Last_Mux); + Els_Inst : Instance; + Els_Clk : Net; + Els_En : Net; begin -- There must be no 'else' part for clock expression. - if not Is_Prev_FF_Value (Get_Driver (I0), Prev_Val, Off) then - Error_Msg_Synth - (+Stmt, "synchronous code does not expect else part"); - return Prev_Val; + Els := Get_Driver (I0); + if Is_Prev_FF_Value (Els, Prev_Val, Off) then + -- The loop. + Els := No_Net; + else + Els_Inst := Get_Net_Parent (Els); + if Get_Id (Els_Inst) = Id_Mux2 then + Extract_Clock (Ctxt, Get_Driver (Get_Mux2_Sel (Els_Inst)), + Els_Clk, Els_En); + else + Els_Clk := No_Net; + end if; + if Els_Clk = No_Net then + Error_Msg_Synth + (+Stmt, "clocked logic requires clocked logic on else part"); + Els := No_Net; + else + Els := Infere_FF (Ctxt, Prev_Val, Off, Els_Inst, + Els_Clk, Els_En, Stmt); + end if; end if; Disconnect (Sel); @@ -471,6 +492,8 @@ package body Netlists.Inference is end loop; end; + Free_Instance (Last_Mux); + if Off = 0 and then Can_Infere_RAM (Data, Prev_Val) then @@ -493,12 +516,25 @@ package body Netlists.Inference is -- Create the FF. if Rst = No_Net then pragma Assert (Rst_Val = No_Net); - if Init /= No_Net then - Res := Build_Idff (Ctxt, Clk, D => Data, Init => Init); + if Els = No_Net then + if Init /= No_Net then + Res := Build_Idff (Ctxt, Clk, D => Data, Init => Init); + else + Res := Build_Dff (Ctxt, Clk, D => Data); + end if; else - Res := Build_Dff (Ctxt, Clk, D => Data); + if Init /= No_Net then + raise Internal_Error; + else + Res := Build_Mdff (Ctxt, Clk, D => Data, Els => Els); + end if; end if; else + if Els /= No_Net then + Error_Msg_Synth + (+Stmt, "synchronous code does not expect else part"); + end if; + if Init /= No_Net then Res := Build_Iadff (Ctxt, Clk, D => Data, Rst => Rst, Rst_Val => Rst_Val, @@ -508,9 +544,7 @@ package body Netlists.Inference is Rst => Rst, Rst_Val => Rst_Val); end if; end if; - Copy_Location (Res, Last_Mux); - - Free_Instance (Last_Mux); + Set_Location (Res, Mux_Loc); return Res; end Infere_FF; |