diff --git a/GD32E508_DCU_APP/device/spi/app_spi_command.cpp b/GD32E508_DCU_APP/device/spi/app_spi_command.cpp
index 65fad46..a2b00fc 100644
--- a/GD32E508_DCU_APP/device/spi/app_spi_command.cpp
+++ b/GD32E508_DCU_APP/device/spi/app_spi_command.cpp
@@ -252,11 +252,12 @@ void AppSpiCommand::setSpiReady(bool ready)
 }
 
 /* v2 DATA_READY: PB6 低 = 有待发数据，高 = 队列空。
- * 替代旧 BUSY/READY 语义中所有 setSpiReady 调用。 */
+ * L5：同步 g_localCredit（单缓冲 0/1）。 */
 void AppSpiCommand::updateDataReady()
 {
     const bool has_data = (m_txLen > 0U) || m_ringPending;
     setSpiReady(!has_data);
+    g_localCredit = has_data ? 0U : 1U;
 }
 
 void AppSpiCommand::configureSpi0()
@@ -641,6 +642,8 @@ bool AppSpiCommand::requestEsp32Read(uint8_t frame_type, const uint8_t *payload,
      * 主动按铃帧使用 V2_FLAG_EVENT，session/seq 从 v2 状态全局变量取；
      * session 未建立时 session_id 填 0。 */
     const uint32_t sess = g_v2Active ? g_sessionId : 0U;
+    /* L5：单缓冲 — 装载前 credit 报 1，装载后 updateDataReady 置 0 */
+    g_localCredit = 1U;
     size_t built_len = 0U;
     if (!v2_build_frame(frame_type, V2_FLAG_EVENT, sess,
                         g_txSeq, 0U, (uint8_t)g_localCredit,
@@ -661,7 +664,7 @@ bool AppSpiCommand::requestEsp32Read(uint8_t frame_type, const uint8_t *payload,
     m_linkState.onRingStart();
 
     /* v2 DATA_READY: 已设 m_ringPending=true 且 m_txLen>0，
-     * updateDataReady() 据此拉低 PB6，通知 ESP32「有待发数据」。 */
+     * updateDataReady() 据此拉低 PB6，并置 g_localCredit=0。 */
     updateDataReady();
     return true;
 }
diff --git a/GD32E508_DCU_APP/device/spi/app_spi_command.h b/GD32E508_DCU_APP/device/spi/app_spi_command.h
index 30cd9e7..943d854 100644
--- a/GD32E508_DCU_APP/device/spi/app_spi_command.h
+++ b/GD32E508_DCU_APP/device/spi/app_spi_command.h
@@ -118,6 +118,11 @@ public:
      */
     bool requestEsp32Read(uint8_t frame_type, const uint8_t *payload, uint16_t payload_len);
 
+    /** @brief L4 别名：主动事件入队（当前等同 requestEsp32Read）。 */
+    bool enqueueEvent(uint8_t frame_type, const uint8_t *payload, uint16_t payload_len) {
+        return requestEsp32Read(frame_type, payload, payload_len);
+    }
+
     /** @brief 查询当前是否有未读按铃（ESP32 尚未来读）。 */
     bool isRingPending() const { return m_ringPending; }