fhdl/verilog: Improve code presentation.

- Add a LiteX Header/Trailer.
- Add _print_signal function.
- Add more infos to the Header.
- Add separators between blocks of code.
- Align Wire/Reg definition.

litex/gen/fhdl/memory.py

@@ -44,9 +44,9 @@ def memory_emit_verilog(memory, ns, add_data_file):
 
     # Memory Description.
     # -------------------
-    r += "//" + "-"*80 + "\n"
+    r += "//" + "-"*78 + "\n"
     r += f"// Memory {gn(memory)}: {memory.depth}-words x {memory.width}-bit\n"
-    r += "//" + "-"*80 + "\n"
+    r += "//" + "-"*78 + "\n"
     for n, port in enumerate(memory.ports):
         r += f"// Port {n} | "
         if port.async_read:
@@ -150,6 +150,6 @@ def memory_emit_verilog(memory, ns, add_data_file):
         # Read-First/No-Change mode: Data already Read on Data Register.
         if port.mode in [READ_FIRST, NO_CHANGE]:
              r += f"assign {gn(port.dat_r)} = {gn(data_regs[n])};\n"
-    r +=  "//" + "-"*80 + "\n\n"
+    r += "\n\n"
 
     return r

litex/gen/fhdl/verilog.py

@@ -13,6 +13,9 @@
 # This file is Copyright (c) 2018 Robin Ole Heinemann <robin.ole.heinemann@t-online.de>
 # SPDX-License-Identifier: BSD-2-Clause
 
+import time
+import datetime
+
 from functools import partial
 from operator import itemgetter
 import collections
@@ -24,7 +27,50 @@ from migen.fhdl.namer import build_namespace
 from migen.fhdl.conv_output import ConvOutput
 from migen.fhdl.specials import Memory
 
-from litex.build.tools import generated_banner
+from litex.build.tools import get_litex_git_revision
+
+# ------------------------------------------------------------------------------------------------ #
+#                                     BANNER/TRAILER/SEPARATORS                                    #
+# ------------------------------------------------------------------------------------------------ #
+
+def _print_banner(filename, device):
+    return """\
+// -----------------------------------------------------------------------------
+// Auto-Generated by:        __   _ __      _  __
+//                          / /  (_) /____ | |/_/
+//                         / /__/ / __/ -_)>  <
+//                        /____/_/\\__/\\__/_/|_|
+//                     Build your hardware, easily!
+//                   https://github.com/enjoy-digital/litex
+//
+// Filename   : {filename}.v
+// Device     : {device}
+// LiteX sha1 : {revision}
+// Date       : {date}
+//------------------------------------------------------------------------------\n
+""".format(
+    device   = device,
+    filename = filename,
+    revision = get_litex_git_revision(),
+    date     = datetime.datetime.fromtimestamp(time.time()).strftime("%Y-%m-%d %H:%M:%S")
+)
+
+def _print_trailer():
+    return """
+// -----------------------------------------------------------------------------
+//  Auto-Generated by LiteX on {date}.
+//------------------------------------------------------------------------------
+""".format(
+    date=datetime.datetime.fromtimestamp(time.time()).strftime("%Y-%m-%d %H:%M:%S")
+)
+
+def _print_separator(msg=""):
+    r =  "\n"
+    r +=  "//" + "-"*78 + "\n"
+    r += f"// {msg}\n"
+    r +=  "//" + "-"*78 + "\n"
+    r += "\n"
+    return r
 
 # ------------------------------------------------------------------------------------------------ #
 #                                    RESERVED KEYWORDS                                             #
@@ -333,7 +379,8 @@ def _print_module(f, ios, name, ns, attr_translate):
     inouts       = list_special_ios(f, ins=False, outs=False, inouts=True)
     targets      = list_targets(f) | special_outs
     wires        = _list_comb_wires(f) | special_outs
-    r = "module " + name + "(\n"
+
+    r = f"module {name} (\n"
     firstp = True
     for sig in sorted(ios, key=lambda x: x.duid):
         if not firstp:
@@ -348,7 +395,7 @@ def _print_module(f, ios, name, ns, attr_translate):
             sig.direction = "inout"
             r += "\tinout  wire " + _print_signal(ns, sig)
         elif sig in targets:
-            sig.direction = "output"
+            sig.direction = "output      "
             if sig in wires:
                 r += "\toutput wire " + _print_signal(ns, sig)
             else:
@@ -358,6 +405,17 @@ def _print_module(f, ios, name, ns, attr_translate):
             sig.direction = "input"
             r += "\tinput  wire " + _print_signal(ns, sig)
     r += "\n);\n\n"
+
+    return r
+
+def _print_signals(f, ios, name, ns, attr_translate):
+    sigs = list_signals(f) | list_special_ios(f, ins=True, outs=True, inouts=True)
+    special_outs = list_special_ios(f, ins=False, outs=True,  inouts=True)
+    inouts       = list_special_ios(f, ins=False, outs=False, inouts=True)
+    targets      = list_targets(f) | special_outs
+    wires        = _list_comb_wires(f) | special_outs
+
+    r = ""
     for sig in sorted(sigs - ios, key=lambda x: x.duid):
         attr = _print_attribute(sig.attr, attr_translate)
         if attr:
@@ -366,7 +424,6 @@ def _print_module(f, ios, name, ns, attr_translate):
             r += "wire " + _print_signal(ns, sig) + ";\n"
         else:
             r += "reg  " + _print_signal(ns, sig) + " = " + _print_expression(ns, sig.reset)[0] + ";\n"
-    r += "\n"
     return r
 
 # ------------------------------------------------------------------------------------------------ #
@@ -525,27 +582,40 @@ def convert(f, ios=set(), name="top", platform=None,
 
     # Build Verilog.
     # --------------
-    verilog = generated_banner("//")
+    verilog = ""
+    verilog += _print_banner(
+        filename = name,
+        device   = getattr(platform, "device", "Unknown")
+    )
 
-    # Module Top.
+    # Module Definition.
+    verilog += _print_separator("Module")
     verilog += _print_module(f, ios, name, ns, attr_translate)
 
+    # Module Signals.
+    verilog += _print_separator("Signals")
+    verilog += _print_signals(f, ios, name, ns, attr_translate)
+
     # Combinatorial Logic.
+    verilog += _print_separator("Combinatorial Logic")
     if regular_comb:
         verilog += _print_combinatorial_logic_synth(f, ns)
     else:
         verilog += _print_combinatorial_logic_sim(f, ns)
 
     # Synchronous Logic.
+    verilog += _print_separator("Synchronous Logic")
     verilog += _print_synchronous_logic(f, ns)
 
     # Specials
+    verilog += _print_separator("Specialized Logic")
     verilog += _print_specials(special_overrides, f.specials - lowered_specials,
         ns, r.add_data_file, attr_translate)
 
     # Module End.
     verilog += "endmodule\n"
 
+    verilog += _print_trailer()
 
     r.set_main_source(verilog)
     r.ns = ns