diff --git a/Src/CanSerialPortFrame.c b/Src/CanSerialPortFrame.c
index 8dfe580..00424ce 100644
--- a/Src/CanSerialPortFrame.c
+++ b/Src/CanSerialPortFrame.c
@@ -202,7 +202,7 @@ void vCanSerialPortFrameDMAInit(
         env->tMbCfg.pRxBuf = CAN_GET_BUFFER(CAN_INDEX);
 
         // tx config
-        env->tMbCfg.u8TxMsgCnt = 6U; // tx occupy 3 mb
+        env->tMbCfg.u8TxMsgCnt = 3U; // tx occupy 3 mb
 
         tRetVal = FLEXCAN_RxFilterConfig(CAN_INDEX, &env->tMbCfg);