diff --git a/usb_mem.c b/usb_mem.c
new file mode 100644
--- /dev/null
+++ b/usb_mem.c
@@ -0,0 +1,87 @@
+/**
+  ******************************************************************************
+  * @file    usb_mem.c
+  * @author  MCD Application Team
+  * @version V4.0.0
+  * @date    28-August-2012
+  * @brief   Utility functions for memory transfers to/from PMA
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
+  *
+  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
+  * You may not use this file except in compliance with the License.
+  * You may obtain a copy of the License at:
+  *
+  *        http://www.st.com/software_license_agreement_liberty_v2
+  *
+  * Unless required by applicable law or agreed to in writing, software 
+  * distributed under the License is distributed on an "AS IS" BASIS, 
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  *
+  ******************************************************************************
+  */
+
+/* Includes ------------------------------------------------------------------*/
+#include "usb_lib.h"
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Extern variables ----------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/*******************************************************************************
+* Function Name  : UserToPMABufferCopy
+* Description    : Copy a buffer from user memory area to packet memory area (PMA)
+* Input          : - pbUsrBuf: pointer to user memory area.
+*                  - wPMABufAddr: address into PMA.
+*                  - wNBytes: no. of bytes to be copied.
+* Output         : None.
+* Return         : None	.
+*******************************************************************************/
+void UserToPMABufferCopy(uint8_t *pbUsrBuf, uint16_t wPMABufAddr, uint16_t wNBytes)
+{
+  uint32_t n = (wNBytes + 1) >> 1;   /* n = (wNBytes + 1) / 2 */
+  uint32_t i, temp1, temp2;
+  uint16_t *pdwVal;
+  pdwVal = (uint16_t *)(wPMABufAddr * 2 + PMAAddr);
+  for (i = n; i != 0; i--)
+  {
+    temp1 = (uint16_t) * pbUsrBuf;
+    pbUsrBuf++;
+    temp2 = temp1 | (uint16_t) * pbUsrBuf << 8;
+    *pdwVal++ = temp2;
+    pdwVal++;
+    pbUsrBuf++;
+  }
+}
+
+/*******************************************************************************
+* Function Name  : PMAToUserBufferCopy
+* Description    : Copy a buffer from user memory area to packet memory area (PMA)
+* Input          : - pbUsrBuf    = pointer to user memory area.
+*                  - wPMABufAddr = address into PMA.
+*                  - wNBytes     = no. of bytes to be copied.
+* Output         : None.
+* Return         : None.
+*******************************************************************************/
+void PMAToUserBufferCopy(uint8_t *pbUsrBuf, uint16_t wPMABufAddr, uint16_t wNBytes)
+{
+  uint32_t n = (wNBytes + 1) >> 1;/* /2*/
+  uint32_t i;
+  uint32_t *pdwVal;
+  pdwVal = (uint32_t *)(wPMABufAddr * 2 + PMAAddr);
+  for (i = n; i != 0; i--)
+  {
+    *(uint16_t*)pbUsrBuf++ = *pdwVal++;
+    pbUsrBuf++;
+  }
+}
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/