From 25152fe4de245f7030e03d53d26d8bdddd7079f1 Mon Sep 17 00:00:00 2001
From: Franck Jullien <franck.jullien@collshade.fr>
Date: Thu, 3 Feb 2022 13:47:30 +0100
Subject: [PATCH] video: align hsync and vsync generated by the vtg

---
 litex/soc/cores/video.py | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/litex/soc/cores/video.py b/litex/soc/cores/video.py
index a16e2001e..81f83c72b 100644
--- a/litex/soc/cores/video.py
+++ b/litex/soc/cores/video.py
@@ -242,21 +242,23 @@ class VideoTimingGenerator(Module, AutoCSR):
                 # Increment HCount.
                 NextValue(source.hcount, source.hcount + 1),
                 # Generate HActive / HSync.
-                If(source.hcount == 0,           NextValue(hactive,      1)), # Start of HActive.
-                If(source.hcount == hres,        NextValue(hactive,      0)), # End of HActive.
-                If(source.hcount == hsync_start, NextValue(source.hsync, 1)), # Start of HSync.
-                If(source.hcount == hsync_end,   NextValue(source.hsync, 0)), # End of HSync.
+                If(source.hcount == 0,             NextValue(hactive,       1)), # Start of HActive.
+                If(source.hcount == hres,          NextValue(hactive,       0)), # End of HActive.
+                If(source.hcount == hsync_start,
+                    NextValue(source.hsync, 1),                                  # Start of HSync.
+                    NextValue(source.vsync, 1),                                  # Start of VSync.
+                    NextValue(source.vcount, vsync_start)
+                ),
+                If(source.hcount == hsync_end,     NextValue(source.hsync,  0)), # End of HSync.
+                If(source.hcount == hscan,         NextValue(source.hcount, 0)), # Reset HCount.
                 # End of HScan.
-                If(source.hcount == hscan,
-                    # Reset HCount.
-                    NextValue(source.hcount, 0),
+                If(source.hcount == hsync_start,
                     # Increment VCount.
                     NextValue(source.vcount, source.vcount + 1),
                     # Generate VActive / VSync.
-                    If(source.vcount == 0,           NextValue(vactive,      1)), # Start of VActive.
-                    If(source.vcount == vres,        NextValue(vactive,      0)), # End of HActive.
-                    If(source.vcount == vsync_start, NextValue(source.vsync, 1)), # Start of VSync.
-                    If(source.vcount == vsync_end,   NextValue(source.vsync, 0)), # End of VSync.
+                    If(source.vcount == 0,         NextValue(vactive,       1)), # Start of VActive.
+                    If(source.vcount == vres,      NextValue(vactive,       0)), # End of HActive.
+                    If(source.vcount == vsync_end, NextValue(source.vsync,  0)), # End of VSync.
                     # End of VScan.
                     If(source.vcount == vscan,
                         # Reset VCount.