diff --git a/analysis/session_state.md b/analysis/session_state.md
index 398483e..7ea2b98 100644
--- a/analysis/session_state.md
+++ b/analysis/session_state.md
@@ -19,7 +19,10 @@
 - [x] 零像素根因定位与修复（load_ddt 表错位）
 - [x] **颗粒感修复**：demo3 显示层改为官方同款 320×240（2x 平滑灰度 +
       调色板 + HALFTONE 放大），同场景 RGB 直方图相关性 0.9796
-- [x] 仓库整理 + csdk/README.md 完整文档 + 本地 commit 0bfb926
+- [x] **FFC 频率对齐**：补官方"启动强制 FFC"逻辑（mode 0 帧 75 无条件
+      FFC(0)，trace 实测启动阶段 FFC(0) 间隔 59~394 帧 ≈ 4~26s，
+      稳定后 1800 帧 ≈ 120s，demo3 已一致）
+- [x] 仓库整理 + csdk/README.md 完整文档 + 本地 commit 0bfb926 / 03ed936
 - [ ] push（等服务器上线，用户手动）
 
 ## 颗粒感问题（已解决，2026-08-14）
diff --git a/build-artifacts/mag160c_demo3.exe b/build-artifacts/mag160c_demo3.exe
index 779667d..6501dba 100644
--- a/build-artifacts/mag160c_demo3.exe
+++ b/build-artifacts/mag160c_demo3.exe
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:a6a6d7a3f5bdcf81d983302e5bcb31d8b8c48094970bd0314418eb7c2886903e
-size 139029
+oid sha256:46c20bd002e372e36742bca1a2244e8a7d9f03dd27989e7c2153f0937b09f98b
+size 139066
diff --git a/csdk/tools/mag160c_demo3.c b/csdk/tools/mag160c_demo3.c
index 72db744..b84c1d8 100644
--- a/csdk/tools/mag160c_demo3.c
+++ b/csdk/tools/mag160c_demo3.c
@@ -132,6 +132,7 @@ static int g_ref_cnt;
 static int g_f20[NPIX];
 static int g_fcount;
 static int g_manual_ffc;
+static int g_startup_ffc_done;
 
 /* ---- render state ---- */
 static unsigned short g_nuc[NPIX];
@@ -927,12 +928,21 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmd, int show) {
         if (idx <= OFF_N0 + OFF_N2 + OFF_N1) {
             continue;
         }
-        /* normal frame: FFC condition */
+        /* normal frame: FFC condition (FUN_180009ee0) */
         {
             int drift = g_shutter - g_shutter_at_ffc;
             if (drift < 0) drift = -drift;
             int cool = OFF_N0 + OFF_N2 + OFF_N1;
             int do_ffc = 0;
+            /* startup forced FFCs (official): mode 0/3/5/6 forces FFC(0)
+             * at frame 75 once; mode 1/2/4 forces at frame 117 up to 5
+             * times.  We do not know the live 0x2d47 mode on Windows, so
+             * follow the mode-0 rule (matches the observed trace cadence:
+             * an extra FFC shortly after startup). */
+            if (!g_startup_ffc_done && idx == 75) {
+                g_startup_ffc_done = 1;
+                do_ffc = 1;
+            }
             if (idx >= OFF_N0 + OFF_FFC_PERIOD)
                 do_ffc = 1;
             else if (idx >= cool + 30 && drift > OFF_FFC_DRIFT)
@@ -941,7 +951,8 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmd, int show) {
                 sendcmd(0x6bb6b672, 0, 8);
                 g_ffc_idx = 0;
                 g_shutter_at_ffc = shutter;
-                if (ffcdbg) { fprintf(ffcdbg, "frame=%u AUTO FFC(0) idx=%d drift=%d\n", g_global_frames, idx, drift); fflush(ffcdbg); }
+                if (ffcdbg) { fprintf(ffcdbg, "frame=%u AUTO FFC(0) idx=%d drift=%d%s\n", g_global_frames, idx, drift,
+                                      g_startup_ffc_done && idx == 75 ? " (forced75)" : ""); fflush(ffcdbg); }
                 continue;
             }
         }