usb

Dependencies:   mbed FatFileSystemCpp

Revision:
1:ad941ffd64cb
Parent:
0:e294af8d0e07
diff -r e294af8d0e07 -r ad941ffd64cb USBHostLite/usbhost_lpc17xx.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USBHostLite/usbhost_lpc17xx.cpp	Mon Jul 30 12:18:24 2012 +0000
@@ -0,0 +1,820 @@
+/*
+**************************************************************************************************************
+*                                                 NXP USB Host Stack
+*
+*                                     (c) Copyright 2008, NXP SemiConductors
+*                                     (c) Copyright 2008, OnChip  Technologies LLC
+*                                                 All Rights Reserved
+*
+*                                                  www.nxp.com
+*                                               www.onchiptech.com
+*
+* File           : usbhost_lpc17xx.c
+* Programmer(s)  : Ravikanth.P
+* Version        :
+*
+**************************************************************************************************************
+*/
+ 
+/*
+**************************************************************************************************************
+*                                            INCLUDE HEADER FILES
+**************************************************************************************************************
+*/
+
+#include  "usbhost_lpc17xx.h"
+
+/*
+**************************************************************************************************************
+*                                              GLOBAL VARIABLES
+**************************************************************************************************************
+*/
+int gUSBConnected;
+
+volatile  USB_INT32U   HOST_RhscIntr = 0;         /* Root Hub Status Change interrupt                       */
+volatile  USB_INT32U   HOST_WdhIntr  = 0;         /* Semaphore to wait until the TD is submitted            */
+volatile  USB_INT08U   HOST_TDControlStatus = 0;
+volatile  HCED        *EDCtrl;                    /* Control endpoint descriptor structure                  */
+volatile  HCED        *EDBulkIn;                  /* BulkIn endpoint descriptor  structure                  */
+volatile  HCED        *EDBulkOut;                 /* BulkOut endpoint descriptor structure                  */
+volatile  HCTD        *TDHead;                    /* Head transfer descriptor structure                     */
+volatile  HCTD        *TDTail;                    /* Tail transfer descriptor structure                     */
+volatile  HCCA        *Hcca;                      /* Host Controller Communications Area structure          */ 
+          USB_INT16U  *TDBufNonVol;               /* Identical to TDBuffer just to reduce compiler warnings */
+volatile  USB_INT08U  *TDBuffer;                  /* Current Buffer Pointer of transfer descriptor          */
+
+// USB host structures
+// AHB SRAM block 1
+#define HOSTBASEADDR 0x2007C000
+// reserve memory for the linker
+static USB_INT08U HostBuf[0x200] __attribute__((at(HOSTBASEADDR)));
+/*
+**************************************************************************************************************
+*                                         DELAY IN MILLI SECONDS
+*
+* Description: This function provides a delay in milli seconds
+*
+* Arguments  : delay    The delay required
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  Host_DelayMS (USB_INT32U  delay)
+{
+    volatile  USB_INT32U  i;
+
+
+    for (i = 0; i < delay; i++) {
+        Host_DelayUS(1000);
+    }
+}
+
+/*
+**************************************************************************************************************
+*                                         DELAY IN MICRO SECONDS
+*
+* Description: This function provides a delay in micro seconds
+*
+* Arguments  : delay    The delay required
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  Host_DelayUS (USB_INT32U  delay)
+{
+    volatile  USB_INT32U  i;
+
+
+    for (i = 0; i < (4 * delay); i++) {    /* This logic was tested. It gives app. 1 micro sec delay        */
+        ;
+    }
+}
+
+// bits of the USB/OTG clock control register
+#define HOST_CLK_EN     (1<<0)
+#define DEV_CLK_EN      (1<<1)
+#define PORTSEL_CLK_EN  (1<<3)
+#define AHB_CLK_EN      (1<<4)
+
+// bits of the USB/OTG clock status register
+#define HOST_CLK_ON     (1<<0)
+#define DEV_CLK_ON      (1<<1)
+#define PORTSEL_CLK_ON  (1<<3)
+#define AHB_CLK_ON      (1<<4)
+
+// we need host clock, OTG/portsel clock and AHB clock
+#define CLOCK_MASK (HOST_CLK_EN | PORTSEL_CLK_EN | AHB_CLK_EN)
+
+/*
+**************************************************************************************************************
+*                                         INITIALIZE THE HOST CONTROLLER
+*
+* Description: This function initializes lpc17xx host controller
+*
+* Arguments  : None
+*
+* Returns    : 
+*
+**************************************************************************************************************
+*/
+void  Host_Init (void)
+{
+    PRINT_Log("In Host_Init\n");
+    NVIC_DisableIRQ(USB_IRQn);                           /* Disable the USB interrupt source           */
+    
+    // turn on power for USB
+    LPC_SC->PCONP       |= (1UL<<31);
+    // Enable USB host clock, port selection and AHB clock
+    LPC_USB->USBClkCtrl |= CLOCK_MASK;
+    // Wait for clocks to become available
+    while ((LPC_USB->USBClkSt & CLOCK_MASK) != CLOCK_MASK)
+        ;
+    
+    // it seems the bits[0:1] mean the following
+    // 0: U1=device, U2=host
+    // 1: U1=host, U2=host
+    // 2: reserved
+    // 3: U1=host, U2=device
+    // NB: this register is only available if OTG clock (aka "port select") is enabled!!
+    // since we don't care about port 2, set just bit 0 to 1 (U1=host)
+    LPC_USB->OTGStCtrl |= 1;
+    
+    // now that we've configured the ports, we can turn off the portsel clock
+    LPC_USB->USBClkCtrl &= ~PORTSEL_CLK_EN;
+    
+    // power pins are not connected on mbed, so we can skip them
+    /* P1[18] = USB_UP_LED, 01 */
+    /* P1[19] = /USB_PPWR,     10 */
+    /* P1[22] = USB_PWRD, 10 */
+    /* P1[27] = /USB_OVRCR, 10 */
+    /*LPC_PINCON->PINSEL3 &= ~((3<<4) | (3<<6) | (3<<12) | (3<<22));  
+    LPC_PINCON->PINSEL3 |=  ((1<<4)|(2<<6) | (2<<12) | (2<<22));   // 0x00802080
+    */
+
+    // configure USB D+/D- pins
+    /* P0[29] = USB_D+, 01 */
+    /* P0[30] = USB_D-, 01 */
+    LPC_PINCON->PINSEL1 &= ~((3<<26) | (3<<28));  
+    LPC_PINCON->PINSEL1 |=  ((1<<26)|(1<<28));     // 0x14000000
+        
+    PRINT_Log("Initializing Host Stack\n");
+
+    Hcca       = (volatile  HCCA       *)(HostBuf+0x000);
+    TDHead     = (volatile  HCTD       *)(HostBuf+0x100);
+    TDTail     = (volatile  HCTD       *)(HostBuf+0x110);
+    EDCtrl     = (volatile  HCED       *)(HostBuf+0x120); 
+    EDBulkIn   = (volatile  HCED       *)(HostBuf+0x130);
+    EDBulkOut  = (volatile  HCED       *)(HostBuf+0x140);
+    TDBuffer   = (volatile  USB_INT08U *)(HostBuf+0x150);
+    
+    /* Initialize all the TDs, EDs and HCCA to 0  */
+    Host_EDInit(EDCtrl);
+    Host_EDInit(EDBulkIn);
+    Host_EDInit(EDBulkOut);
+    Host_TDInit(TDHead);
+    Host_TDInit(TDTail);
+    Host_HCCAInit(Hcca);
+    
+    Host_DelayMS(50);                                   /* Wait 50 ms before apply reset              */
+    LPC_USB->HcControl       = 0;                       /* HARDWARE RESET                             */
+    LPC_USB->HcControlHeadED = 0;                       /* Initialize Control list head to Zero       */
+    LPC_USB->HcBulkHeadED    = 0;                       /* Initialize Bulk list head to Zero          */
+    
+                                                        /* SOFTWARE RESET                             */
+    LPC_USB->HcCommandStatus = OR_CMD_STATUS_HCR;
+    LPC_USB->HcFmInterval    = DEFAULT_FMINTERVAL;      /* Write Fm Interval and Largest Data Packet Counter */
+
+                                                        /* Put HC in operational state                */
+    LPC_USB->HcControl  = (LPC_USB->HcControl & (~OR_CONTROL_HCFS)) | OR_CONTROL_HC_OPER;
+    LPC_USB->HcRhStatus = OR_RH_STATUS_LPSC;            /* Set Global Power                           */
+    
+    LPC_USB->HcHCCA = (USB_INT32U)Hcca;
+    LPC_USB->HcInterruptStatus |= LPC_USB->HcInterruptStatus;                   /* Clear Interrrupt Status                    */
+
+
+    LPC_USB->HcInterruptEnable  = OR_INTR_ENABLE_MIE |
+                         OR_INTR_ENABLE_WDH |
+                         OR_INTR_ENABLE_RHSC;
+
+    NVIC_SetPriority(USB_IRQn, 0);       /* highest priority */
+    /* Enable the USB Interrupt */
+    NVIC_EnableIRQ(USB_IRQn);
+    PRINT_Log("Host Initialized\n");
+}
+
+/*
+**************************************************************************************************************
+*                                         INTERRUPT SERVICE ROUTINE
+*
+* Description: This function services the interrupt caused by host controller
+*
+* Arguments  : None
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void USB_IRQHandler (void) __irq
+{
+    USB_INT32U   int_status;
+    USB_INT32U   ie_status;
+
+    int_status    = LPC_USB->HcInterruptStatus;                          /* Read Interrupt Status                */
+    ie_status     = LPC_USB->HcInterruptEnable;                          /* Read Interrupt enable status         */
+ 
+    if (!(int_status & ie_status)) {
+        return;
+    } else {
+
+        int_status = int_status & ie_status;
+        if (int_status & OR_INTR_STATUS_RHSC) {                 /* Root hub status change interrupt     */
+            if (LPC_USB->HcRhPortStatus1 & OR_RH_PORT_CSC) {
+                if (LPC_USB->HcRhStatus & OR_RH_STATUS_DRWE) {
+                    /*
+                     * When DRWE is on, Connect Status Change
+                     * means a remote wakeup event.
+                    */
+                    HOST_RhscIntr = 1;// JUST SOMETHING FOR A BREAKPOINT
+                }
+                else {
+                    /*
+                     * When DRWE is off, Connect Status Change
+                     * is NOT a remote wakeup event
+                    */
+                    if (LPC_USB->HcRhPortStatus1 & OR_RH_PORT_CCS) {
+                        if (!gUSBConnected) {
+                            HOST_TDControlStatus = 0;
+                            HOST_WdhIntr = 0;
+                            HOST_RhscIntr = 1;
+                            gUSBConnected = 1;
+                        }
+                        else
+                            PRINT_Log("Spurious status change (connected)?\n");
+                    } else {
+                        if (gUSBConnected) {
+                            LPC_USB->HcInterruptEnable = 0; // why do we get multiple disc. rupts???
+                            HOST_RhscIntr = 0;
+                            gUSBConnected = 0;
+                        }
+                        else
+                            PRINT_Log("Spurious status change (disconnected)?\n");
+                    }
+                }
+                LPC_USB->HcRhPortStatus1 = OR_RH_PORT_CSC;
+            }
+            if (LPC_USB->HcRhPortStatus1 & OR_RH_PORT_PRSC) {
+                LPC_USB->HcRhPortStatus1 = OR_RH_PORT_PRSC;
+            }
+        }
+        if (int_status & OR_INTR_STATUS_WDH) {                  /* Writeback Done Head interrupt        */
+            HOST_WdhIntr = 1;
+            HOST_TDControlStatus = (TDHead->Control >> 28) & 0xf;
+        }            
+        LPC_USB->HcInterruptStatus = int_status;                         /* Clear interrupt status register      */
+    }
+    return;
+}
+
+/*
+**************************************************************************************************************
+*                                     PROCESS TRANSFER DESCRIPTOR
+*
+* Description: This function processes the transfer descriptor
+*
+* Arguments  : ed            Endpoint descriptor that contains this transfer descriptor
+*              token         SETUP, IN, OUT
+*              buffer        Current Buffer Pointer of the transfer descriptor
+*              buffer_len    Length of the buffer
+*
+* Returns    : OK       if TD submission is successful
+*              ERROR    if TD submission fails
+*
+**************************************************************************************************************
+*/
+
+USB_INT32S  Host_ProcessTD (volatile  HCED       *ed,
+                            volatile  USB_INT32U  token,
+                            volatile  USB_INT08U *buffer,
+                                      USB_INT32U  buffer_len)
+{
+    volatile  USB_INT32U   td_toggle;
+
+
+    if (ed == EDCtrl) {
+        if (token == TD_SETUP) {
+            td_toggle = TD_TOGGLE_0;
+        } else {
+            td_toggle = TD_TOGGLE_1;
+        }
+    } else {
+        td_toggle = 0;
+    }
+    TDHead->Control = (TD_ROUNDING    |
+                      token           |
+                      TD_DELAY_INT(0) |                           
+                      td_toggle       |
+                      TD_CC);
+    TDTail->Control = 0;
+    TDHead->CurrBufPtr   = (USB_INT32U) buffer;
+    TDTail->CurrBufPtr   = 0;
+    TDHead->Next         = (USB_INT32U) TDTail;
+    TDTail->Next         = 0;
+    TDHead->BufEnd       = (USB_INT32U)(buffer + (buffer_len - 1));
+    TDTail->BufEnd       = 0;
+
+    ed->HeadTd  = (USB_INT32U)TDHead | ((ed->HeadTd) & 0x00000002);
+    ed->TailTd  = (USB_INT32U)TDTail;
+    ed->Next    = 0;
+
+    if (ed == EDCtrl) {
+        LPC_USB->HcControlHeadED = (USB_INT32U)ed;
+        LPC_USB->HcCommandStatus = LPC_USB->HcCommandStatus | OR_CMD_STATUS_CLF;
+        LPC_USB->HcControl       = LPC_USB->HcControl       | OR_CONTROL_CLE;
+    } else {
+        LPC_USB->HcBulkHeadED    = (USB_INT32U)ed;
+        LPC_USB->HcCommandStatus = LPC_USB->HcCommandStatus | OR_CMD_STATUS_BLF;
+        LPC_USB->HcControl       = LPC_USB->HcControl       | OR_CONTROL_BLE;
+    }    
+
+    Host_WDHWait();
+
+//    if (!(TDHead->Control & 0xF0000000)) {
+    if (!HOST_TDControlStatus) {
+        return (OK);
+    } else {      
+        return (ERR_TD_FAIL);
+    }
+}
+
+/*
+**************************************************************************************************************
+*                                       ENUMERATE THE DEVICE
+*
+* Description: This function is used to enumerate the device connected
+*
+* Arguments  : None
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+USB_INT32S  Host_EnumDev (void)
+{
+    USB_INT32S  rc;
+
+    PRINT_Log("Connect a Mass Storage device\n");
+    while (!HOST_RhscIntr)
+        __WFI();
+    Host_DelayMS(100);                             /* USB 2.0 spec says atleast 50ms delay beore port reset */
+    LPC_USB->HcRhPortStatus1 = OR_RH_PORT_PRS; // Initiate port reset
+    while (LPC_USB->HcRhPortStatus1 & OR_RH_PORT_PRS)
+        __WFI(); // Wait for port reset to complete...
+    LPC_USB->HcRhPortStatus1 = OR_RH_PORT_PRSC; // ...and clear port reset signal
+    Host_DelayMS(200);                                                 /* Wait for 100 MS after port reset  */
+
+    EDCtrl->Control = 8 << 16;                                         /* Put max pkt size = 8              */
+                                                                       /* Read first 8 bytes of device desc */
+    rc = HOST_GET_DESCRIPTOR(USB_DESCRIPTOR_TYPE_DEVICE, 0, TDBuffer, 8);
+    if (rc != OK) {
+        PRINT_Err(rc);
+        return (rc);
+    }
+    EDCtrl->Control = TDBuffer[7] << 16;                               /* Get max pkt size of endpoint 0    */
+    rc = HOST_SET_ADDRESS(1);                                          /* Set the device address to 1       */
+    if (rc != OK) {
+        PRINT_Err(rc);
+        return (rc);
+    }
+    Host_DelayMS(2);
+    EDCtrl->Control = (EDCtrl->Control) | 1;                          /* Modify control pipe with address 1 */
+                                                                      /* Get the configuration descriptor   */
+    rc = HOST_GET_DESCRIPTOR(USB_DESCRIPTOR_TYPE_CONFIGURATION, 0, TDBuffer, 9);
+    if (rc != OK) {
+        PRINT_Err(rc);
+        return (rc);
+    }
+                                                                       /* Get the first configuration data  */
+    rc = HOST_GET_DESCRIPTOR(USB_DESCRIPTOR_TYPE_CONFIGURATION, 0, TDBuffer, ReadLE16U(&TDBuffer[2]));
+    if (rc != OK) {
+        PRINT_Err(rc);
+        return (rc);
+    }
+    rc = MS_ParseConfiguration();                                      /* Parse the configuration           */
+    if (rc != OK) {
+        PRINT_Err(rc);
+        return (rc);
+    }
+    rc = USBH_SET_CONFIGURATION(1);                                    /* Select device configuration 1     */
+    if (rc != OK) {
+        PRINT_Err(rc);
+    }
+    Host_DelayMS(100);                                               /* Some devices may require this delay */
+    return (rc);
+}
+
+/*
+**************************************************************************************************************
+*                                        RECEIVE THE CONTROL INFORMATION
+*
+* Description: This function is used to receive the control information
+*
+* Arguments  : bm_request_type
+*              b_request
+*              w_value
+*              w_index
+*              w_length
+*              buffer
+*
+* Returns    : OK       if Success
+*              ERROR    if Failed
+*
+**************************************************************************************************************
+*/
+   
+USB_INT32S  Host_CtrlRecv (         USB_INT08U   bm_request_type,
+                                    USB_INT08U   b_request,
+                                    USB_INT16U   w_value,
+                                    USB_INT16U   w_index,
+                                    USB_INT16U   w_length,
+                          volatile  USB_INT08U  *buffer)
+{
+    USB_INT32S  rc;
+
+
+    Host_FillSetup(bm_request_type, b_request, w_value, w_index, w_length);
+    rc = Host_ProcessTD(EDCtrl, TD_SETUP, TDBuffer, 8);
+    if (rc == OK) {
+        if (w_length) {
+            rc = Host_ProcessTD(EDCtrl, TD_IN, TDBuffer, w_length);
+        }
+        if (rc == OK) {
+            rc = Host_ProcessTD(EDCtrl, TD_OUT, NULL, 0);
+        }
+    }
+    return (rc);
+}
+
+/*
+**************************************************************************************************************
+*                                         SEND THE CONTROL INFORMATION
+*
+* Description: This function is used to send the control information
+*
+* Arguments  : None
+*
+* Returns    : OK                      if Success
+*              ERR_INVALID_BOOTSIG    if Failed
+*
+**************************************************************************************************************
+*/
+
+USB_INT32S  Host_CtrlSend (          USB_INT08U   bm_request_type,
+                                     USB_INT08U   b_request,
+                                     USB_INT16U   w_value,
+                                     USB_INT16U   w_index,
+                                     USB_INT16U   w_length,
+                           volatile  USB_INT08U  *buffer)
+{
+    USB_INT32S  rc;
+
+
+    Host_FillSetup(bm_request_type, b_request, w_value, w_index, w_length);
+
+    rc = Host_ProcessTD(EDCtrl, TD_SETUP, TDBuffer, 8);
+    if (rc == OK) {
+        if (w_length) {
+            rc = Host_ProcessTD(EDCtrl, TD_OUT, TDBuffer, w_length);
+        }
+        if (rc == OK) {
+            rc = Host_ProcessTD(EDCtrl, TD_IN, NULL, 0);
+        }
+    }
+    return (rc);
+}
+
+/*
+**************************************************************************************************************
+*                                          FILL SETUP PACKET
+*
+* Description: This function is used to fill the setup packet
+*
+* Arguments  : None
+*
+* Returns    : OK                      if Success
+*              ERR_INVALID_BOOTSIG    if Failed
+*
+**************************************************************************************************************
+*/
+
+void  Host_FillSetup (USB_INT08U   bm_request_type,
+                      USB_INT08U   b_request,
+                      USB_INT16U   w_value,
+                      USB_INT16U   w_index,
+                      USB_INT16U   w_length)
+{
+    int i;
+    for (i=0;i<w_length;i++)
+        TDBuffer[i] = 0;
+    
+    TDBuffer[0] = bm_request_type;
+    TDBuffer[1] = b_request;
+    WriteLE16U(&TDBuffer[2], w_value);
+    WriteLE16U(&TDBuffer[4], w_index);
+    WriteLE16U(&TDBuffer[6], w_length);
+}
+
+
+
+/*
+**************************************************************************************************************
+*                                         INITIALIZE THE TRANSFER DESCRIPTOR
+*
+* Description: This function initializes transfer descriptor
+*
+* Arguments  : Pointer to TD structure
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  Host_TDInit (volatile  HCTD *td)
+{
+
+    td->Control    = 0;
+    td->CurrBufPtr = 0;
+    td->Next       = 0;
+    td->BufEnd     = 0;
+}
+
+/*
+**************************************************************************************************************
+*                                         INITIALIZE THE ENDPOINT DESCRIPTOR
+*
+* Description: This function initializes endpoint descriptor
+*
+* Arguments  : Pointer to ED strcuture
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  Host_EDInit (volatile  HCED *ed)
+{
+
+    ed->Control = 0;
+    ed->TailTd  = 0;
+    ed->HeadTd  = 0;
+    ed->Next    = 0;
+}
+
+/*
+**************************************************************************************************************
+*                                 INITIALIZE HOST CONTROLLER COMMUNICATIONS AREA
+*
+* Description: This function initializes host controller communications area
+*
+* Arguments  : Pointer to HCCA
+*
+* Returns    : 
+*
+**************************************************************************************************************
+*/
+
+void  Host_HCCAInit (volatile  HCCA  *hcca)
+{
+    USB_INT32U  i;
+
+
+    for (i = 0; i < 32; i++) {
+
+        hcca->IntTable[i] = 0;
+        hcca->FrameNumber = 0;
+        hcca->DoneHead    = 0;
+    }
+
+}
+
+/*
+**************************************************************************************************************
+*                                         WAIT FOR WDH INTERRUPT
+*
+* Description: This function is infinite loop which breaks when ever a WDH interrupt rises
+*
+* Arguments  : None
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  Host_WDHWait (void)
+{
+  while (!HOST_WdhIntr)
+      __WFI();
+
+  HOST_WdhIntr = 0;
+}
+
+/*
+**************************************************************************************************************
+*                                         READ LE 32U
+*
+* Description: This function is used to read an unsigned integer from a character buffer in the platform
+*              containing little endian processor
+*
+* Arguments  : pmem    Pointer to the character buffer
+*
+* Returns    : val     Unsigned integer
+*
+**************************************************************************************************************
+*/
+
+USB_INT32U  ReadLE32U (volatile  USB_INT08U  *pmem)
+{
+    USB_INT32U val = *(USB_INT32U*)pmem;
+#ifdef __BIG_ENDIAN
+    return __REV(val);
+#else
+    return val;
+#endif    
+}
+
+/*
+**************************************************************************************************************
+*                                        WRITE LE 32U
+*
+* Description: This function is used to write an unsigned integer into a charecter buffer in the platform 
+*              containing little endian processor.
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*              val     Integer value to be placed in the charecter buffer
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  WriteLE32U (volatile  USB_INT08U  *pmem,
+                            USB_INT32U   val)
+{
+#ifdef __BIG_ENDIAN
+    *(USB_INT32U*)pmem = __REV(val);
+#else
+    *(USB_INT32U*)pmem = val;
+#endif
+}
+
+/*
+**************************************************************************************************************
+*                                          READ LE 16U
+*
+* Description: This function is used to read an unsigned short integer from a charecter buffer in the platform
+*              containing little endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*
+* Returns    : val     Unsigned short integer
+*
+**************************************************************************************************************
+*/
+
+USB_INT16U  ReadLE16U (volatile  USB_INT08U  *pmem)
+{
+    USB_INT16U val = *(USB_INT16U*)pmem;
+#ifdef __BIG_ENDIAN
+    return __REV16(val);
+#else
+    return val;
+#endif    
+}
+
+/*
+**************************************************************************************************************
+*                                         WRITE LE 16U
+*
+* Description: This function is used to write an unsigned short integer into a charecter buffer in the
+*              platform containing little endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*              val     Value to be placed in the charecter buffer
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  WriteLE16U (volatile  USB_INT08U  *pmem,
+                            USB_INT16U   val)
+{
+#ifdef __BIG_ENDIAN
+    *(USB_INT16U*)pmem = (__REV16(val) & 0xFFFF);
+#else
+    *(USB_INT16U*)pmem = val;
+#endif
+}
+
+/*
+**************************************************************************************************************
+*                                         READ BE 32U
+*
+* Description: This function is used to read an unsigned integer from a charecter buffer in the platform
+*              containing big endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*
+* Returns    : val     Unsigned integer
+*
+**************************************************************************************************************
+*/
+
+USB_INT32U  ReadBE32U (volatile  USB_INT08U  *pmem)
+{
+    USB_INT32U val = *(USB_INT32U*)pmem;
+#ifdef __BIG_ENDIAN
+    return val;
+#else
+    return __REV(val);
+#endif
+}
+
+/*
+**************************************************************************************************************
+*                                         WRITE BE 32U
+*
+* Description: This function is used to write an unsigned integer into a charecter buffer in the platform
+*              containing big endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*              val     Value to be placed in the charecter buffer
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  WriteBE32U (volatile  USB_INT08U  *pmem,
+                            USB_INT32U   val)
+{
+#ifdef __BIG_ENDIAN
+    *(USB_INT32U*)pmem = val;
+#else
+    *(USB_INT32U*)pmem = __REV(val);
+#endif
+}
+
+/*
+**************************************************************************************************************
+*                                         READ BE 16U
+*
+* Description: This function is used to read an unsigned short integer from a charecter buffer in the platform
+*              containing big endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*
+* Returns    : val     Unsigned short integer
+*
+**************************************************************************************************************
+*/
+
+USB_INT16U  ReadBE16U (volatile  USB_INT08U  *pmem)
+{
+    USB_INT16U val = *(USB_INT16U*)pmem;
+#ifdef __BIG_ENDIAN
+    return val;
+#else
+    return __REV16(val);
+#endif    
+}
+
+/*
+**************************************************************************************************************
+*                                         WRITE BE 16U
+*
+* Description: This function is used to write an unsigned short integer into the charecter buffer in the
+*              platform containing big endian processor
+*
+* Arguments  : pmem    Pointer to the charecter buffer
+*              val     Value to be placed in the charecter buffer
+*
+* Returns    : None
+*
+**************************************************************************************************************
+*/
+
+void  WriteBE16U (volatile  USB_INT08U  *pmem,
+                            USB_INT16U   val)
+{
+#ifdef __BIG_ENDIAN
+    *(USB_INT16U*)pmem = val;
+#else
+    *(USB_INT16U*)pmem = (__REV16(val) & 0xFFFF);
+#endif
+}