diff --git a/Inc/SerialPortFlagchip.h b/Inc/SerialPortFlagchip.h
index 4c4dd97..eaa7b04 100644
--- a/Inc/SerialPortFlagchip.h
+++ b/Inc/SerialPortFlagchip.h
@@ -18,6 +18,9 @@
 #include "fc7xxx_driver_gpio.h"
 #include "fc7xxx_driver_dma.h"
 
+
+#define  UART_RX_FIFO_WATERMARK 15U
+
 typedef struct {
     uint8_t UART_INDEX;
     DMA_ChannelType RX_DMA_CHANNEL;
@@ -26,6 +29,7 @@ typedef struct {
     uint32_t DMA_BUF_LEN;
 
     uint32_t UART_DMA_RECEIVED_LEN_BUF;
+    uint32_t UART_DMA_RECEIVED_POINTER_BUF;
 
     FCUART_DataType s_tFCUART_TxMsg;
 
@@ -42,7 +46,7 @@ typedef struct {
     osMessageQueueId_t txAccessQueue;
     osMessageQueueId_t rxDataQueue;
     osMessageQueueId_t rxDataSnifferQueue;
-    osMessageQueueId_t rxDataSnifferSecondQueue;
+
 } tSerialPortFlagchip;
 
 
diff --git a/Src/SerialPortFlagchip.c b/Src/SerialPortFlagchip.c
index a07d58d..d4c9618 100644
--- a/Src/SerialPortFlagchip.c
+++ b/Src/SerialPortFlagchip.c
@@ -74,9 +74,6 @@ void vSerialPortInitDMA(
         env->rxDataSnifferQueue = 0;
     }
 
-
-    FCUART_InitMemory(UART_INDEX);
-
     env->dmaInitCfg.eArbitrationAlgorithm = DMA_ARBITRATION_ALGORITHM_FIXED_PRIORITY;
     env->dmaInitCfg.bHaltOnError = false;
     DMA_Init(DMA_INSTANCE_0, &env->dmaInitCfg);
@@ -84,6 +81,7 @@ void vSerialPortInitDMA(
     env->chnCfg.pSrcBuffer = &(uart->DATA);
     env->chnCfg.pDestBuffer = DMA_BUF;
     env->chnCfg.u32BlockSize = 1U;
+    //env->chnCfg.u32BlockSize = (UART_RX_FIFO_WATERMARK + 1U);;
     env->chnCfg.u16BlockCount = 1U;
     env->chnCfg.u8ChannelPriority = IRQ_DMA_CHANNEL_PRIORITY;
     env->chnCfg.eSrcDataSize = DMA_TRANSFER_SIZE_1B;
@@ -96,10 +94,17 @@ void vSerialPortInitDMA(
     env->chnCfg.bSrcAddrLoopbackEn = false;
     env->chnCfg.bDestAddrLoopbackEn = false;
     env->chnCfg.bAutoStop = false;
+
+    //env->chnCfg.bSrcCircularBufferEn = false;
+    //env->chnCfg.u32SrcCircBufferSize = 0U;
+    //env->chnCfg.bDestCircularBufferEn = false;
+    //env->chnCfg.u32DestCircBufferSize = 0U;
+
     env->chnCfg.bSrcCircularBufferEn = false;
-    env->chnCfg.u32SrcCircBufferSize = 0U;
-    env->chnCfg.bDestCircularBufferEn = false;
-    env->chnCfg.u32DestCircBufferSize = 0U;
+    env->chnCfg.u32SrcCircBufferSize  = 0U;
+    env->chnCfg.bDestCircularBufferEn = true;
+    env->chnCfg.u32DestCircBufferSize = DMA_BUF_LEN;
+
     env->chnCfg.eTriggerSrc = RX_DMA_CHANNEL_REQ;
     DMA_InitChannel(DMA_INSTANCE_0, RX_DMA_CHANNEL, &env->chnCfg);
 
@@ -111,23 +116,30 @@ void vSerialPortInitDMA(
 
     DMA_StartChannel(DMA_INSTANCE_0, RX_DMA_CHANNEL);
 
-    //NVIC_SetPriorityGrouping(NVIC_PRIORITY_GROUP_4);
-
     NVIC_SetPriority(DMA_Error_IRQn, IRQ_DMA_PRIORITY);
     NVIC_SetPriority(IRQ_DMA, IRQ_DMA_PRIORITY);
     NVIC_EnableIRQ(IRQ_DMA);
 
+
     FCUART_ErrorType tRetVal;
     uint32_t u32PccFuncClk;
 
+    FCUART_InitMemory(UART_INDEX);
+
     u32PccFuncClk = PCC_GetPccFunctionClock(s_ePccUartTable[UART_INDEX]);
 
     if (u32PccFuncClk != 0U) {
         env->tInitCfg.bEnRxFullDma = true;                        // UART receiver full DMA disable
-        env->tInitCfg.bEnRxFifo = false;                          // UART fifo disable
 
-        env->tInitCfg.bEnTxFifo = true;                      // UART tx fifo enable
-        env->tInitCfg.u8TxFifoWaterMark = 0U;                // UART tx fifo 16 bytes trigger
+        //env->tInitCfg.bEnRxFifo = false;                          // UART fifo disable
+        //env->tInitCfg.bEnTxFifo = true;                      // UART tx fifo enable
+        //env->tInitCfg.u8TxFifoWaterMark = 0U;                // UART tx fifo 16 bytes trigger
+
+        env->tInitCfg.bEnTxFifo = true;
+        env->tInitCfg.u8TxFifoWaterMark = 0U;
+
+        env->tInitCfg.bEnRxFifo = true;
+        env->tInitCfg.u8RxFifoWaterMark = 0U;
 
         env->tInitCfg.eIdleCharNum = FCUART_IDLE_CHARCTER_64;     // UART idle character number 64
         env->tInitCfg.eIdleStart = FCUART_START_AFTER_STOPBIT;    // UART idle character type
@@ -162,11 +174,11 @@ void vSerialPortInitDMA(
 
             tRetVal = FCUART_SetInterrupt(UART_INDEX, &env->tInterruptCfg);
 
-            tRetVal = FCUART_StartReceive(UART_INDEX);
-
             NVIC_SetPriority(IRQ_UART, UART_PRIORITY);
             NVIC_EnableIRQ(IRQ_UART);
 
+            tRetVal = FCUART_StartReceive(UART_INDEX);
+
         }
     }
 
@@ -220,14 +232,6 @@ static uint16_t vSerialPortReceiveSniffer(tSerialPortFlagchip *env, uint8_t *dat
            : 0;
 }
 
-static uint16_t
-vSerialPortReceiveSnifferSecond(tSerialPortFlagchip *env, uint8_t *data, uint16_t size, uint32_t timeout) {
-
-    return env->rxDataSnifferSecondQueue
-           ? vSerialPortReceiveQueue(env, data, size, timeout, env->rxDataSnifferSecondQueue)
-           : 0;
-}
-
 
 static uint16_t
 vSerialPortTransmitOverCore(tSerialPortFlagchip *env, uint8_t *data, uint16_t size, uint32_t timeout) {
@@ -236,7 +240,6 @@ vSerialPortTransmitOverCore(tSerialPortFlagchip *env, uint8_t *data, uint16_t si
 
     FCUART_ErrorType tRetVal;
 
-//    memcpy(env->dataBufTransmit, data, size);
     tRetVal = FCUART_AssignTxInterruptData(env->UART_INDEX, env->dataBufTransmit, size);
 
     tRetVal = FCUART_StartTransmit(env->UART_INDEX);
@@ -293,12 +296,3 @@ tSerialPortIO vSerialPortGetSnifferIo(tSerialPortFlagchip *env) {
     };
     return io;
 }
-
-tSerialPortIO SerialPort_GetSnifferSecondIo(tSerialPortFlagchip *env) {
-    tSerialPortIO io = {
-            .env = env,
-            .receive = (SerialPortIOTransaction) vSerialPortReceiveSnifferSecond,
-            .transmit =  vSerialPortTransmitterGet(env)
-    };
-    return io;
-}
\ No newline at end of file