Gavin Lavan
CODE
Dependencies: C12832_lcd CMPS03 FatFileSystemCpp GPS MMA7660 mbed
Fork of
CompleteMbed
by 
Group 14
Diff: USBHostLite/usbhost_lpc17xx.cpp
- Revision:
- 0:2557081b4322
diff -r 000000000000 -r 2557081b4322 USBHostLite/usbhost_lpc17xx.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/USBHostLite/usbhost_lpc17xx.cpp Wed May 07 09:49:54 2014 +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
+}