vcd: creates gtkw file if filter_*.txt file is present

Author: fjullien

litescope/software/dump/vcd.py

@@ -4,6 +4,7 @@
 # Copyright (c) 2015-2018 Florent Kermarrec <[email protected]>
 # SPDX-License-Identifier: BSD-2-Clause
 
+from os.path import exists
 from itertools import count
 import datetime
 import re
@@ -51,6 +52,7 @@ def __init__(self, dump=None, samplerate=1e-12, timescale="1ps", comment=""):
         # factor of 2 scale is because of 2x samples from fake clock
         self.count_timescale = int(1 / (timescale_seconds * samplerate * 2))
         self.timescale_unit_str = si_prefix + "s"
+        self.filtered = []
 
     def change(self):
         r = ""
@@ -128,6 +130,16 @@ def generate_valuechange(self):
             self.cnt += 1
         return r
 
+    def generate_gtkw(self, filename):
+        base_name = filename.split(".")[0]
+        with open("{}.gtkw".format(base_name), "w") as f:
+            f.write(f"[*] Auto-Generated by Litex\n")
+            f.write(f"[dumpfile] {filename}\n")
+            for s in self.filtered:
+                f.write("@2025\n")
+                f.write(f"^1 filter_{s.name}.txt\n")
+                f.write("{}[{}:0]\n".format(s.name, s.width - 1))
+
     def __repr__(self):
         r = ""
         return r
@@ -147,5 +159,12 @@ def write(self, filename):
         f.write(self.generate_valuechange())
         f.close()
 
+        for v in self.variables:
+            if exists(f"filter_{v.name}.txt"):
+                self.filtered.append(v)
+
+        if self.filtered:
+            self.generate_gtkw(filename)
+
     def read(self, filename):
         raise NotImplementedError("VCD files can not (yet) be read, please contribute!")