File content as of revision 0:1802fb31b938:
/*
**************************************************************************************************************
* 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 */
volatile USB_INT08U *FATBuffer; /* Buffer used by FAT file system */
volatile USB_INT08U *UserBuffer; /* Buffer used by application */
/*
**************************************************************************************************************
* 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 */
;
}
}
/*
**************************************************************************************************************
* INITIALIZE THE HOST CONTROLLER
*
* Description: This function initializes lpc17xx host controller
*
* Arguments : None
*
* Returns :
*
**************************************************************************************************************
*/
void Host_Init (void)
{
USB_INT32U HostBaseAddr;
PRINT_Log("In Host_Init, LPC_USB=0x%08X\r\n", LPC_USB);
//NVIC_DisableIRQ(USB_IRQn); /* Disable the USB interrupt source */
LPC_SC->PCONP |= (1UL<<31); // set PCUSB bit
#if 1
PRINT_Log("1: OTGClkCtrl == %08X, OTGClkSt == %08X\r\n", LPC_USB->OTGClkCtrl, LPC_USB->OTGClkSt);
LPC_USB->OTGClkCtrl = 0x0000001F;
PRINT_Log("2: OTGClkCtrl == %08X, OTGClkSt == %08X\r\n", LPC_USB->OTGClkCtrl, LPC_USB->OTGClkSt);
while ((LPC_USB->OTGClkSt & 0x0000001F) == 0) { /* Host clock is available */
;
}
#else
PRINT_Log("1: USBClkCtrl == %08X, USBClkSt == %08X\r\n", LPC_USB->USBClkCtrl, LPC_USB->USBClkSt);
LPC_USB->USBClkCtrl |= 0x01; /* Enable USB host clock */
PRINT_Log("2: USBClkCtrl == %08X, USBClkSt == %08X\r\n", LPC_USB->USBClkCtrl, LPC_USB->USBClkSt);
// while ((LPC_USB->USBClkSt & 0x00000001) == 0) { /* Host clock is available */
// ;
// }
wait(0.5);
#endif
PRINT_Log("3: OTGStCtrl=%08X\r\n", LPC_USB->OTGStCtrl);
#if 1
LPC_USB->OTGStCtrl = 1; // ? 0x3;
PRINT_Log("4\r\n");
#endif
/* P1[18] = USB_UP_LED, 01 */
/* P1[19] = /USB_PPWR, 10 */
/* P1[22] = USB_PWRD, 10 */
/* P1[27] = /USB_OVRCR, 10 */
#if 0
LPC_PINCON->PINSEL3 &= ~((3<<4) | (3<<6) | (3<<12) | (3<<22));
LPC_PINCON->PINSEL3 |= ((1<<4)|(2<<6) | (2<<12) | (2<<22)); // 0x00802080
PRINT_Log("5\r\n");
#endif
/* 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\r\n");
// For chip revision V01 and later
// HostBaseAddr = 0x20080000;
#ifdef TARGET_LPC1768
// mbed's "USB RAM"
HostBaseAddr = 0x2007C000;
#else
// USB RAM
HostBaseAddr = 0x7FD00000;
#endif
Hcca = (volatile HCCA *)(HostBaseAddr+0x000);
TDHead = (volatile HCTD *)(HostBaseAddr+0x100);
TDTail = (volatile HCTD *)(HostBaseAddr+0x110);
EDCtrl = (volatile HCED *)(HostBaseAddr+0x120);
EDBulkIn = (volatile HCED *)(HostBaseAddr+0x130);
EDBulkOut = (volatile HCED *)(HostBaseAddr+0x140);
TDBuffer = (volatile USB_INT08U *)(HostBaseAddr+0x150);
FATBuffer = (volatile USB_INT08U *)(HostBaseAddr+0x1D0);
UserBuffer = (volatile USB_INT08U *)(HostBaseAddr+0x1000);
/* Initialize all the TDs, EDs and HCCA to 0 */
PRINT_Log("6\r\n");
Host_EDInit(EDCtrl);
PRINT_Log("7\r\n");
Host_EDInit(EDBulkIn);
PRINT_Log("8\r\n");
Host_EDInit(EDBulkOut);
PRINT_Log("9\r\n");
Host_TDInit(TDHead);
PRINT_Log("10\r\n");
Host_TDInit(TDTail);
PRINT_Log("11\r\n");
Host_HCCAInit(Hcca);
PRINT_Log("12\r\n");
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;
PRINT_Log("15\r\n");
#ifdef TARGET_LPC2368
NVIC->IntSelect &= ~(1 << USB_IRQn); /* Configure the ISR handler as IRQ */
/* Set the vector address */
NVIC_SetVector(USB_IRQn, (USB_INT32U)USB_IRQHandler);
#endif
NVIC_SetPriority(USB_IRQn, 0); /* highest priority */
/* Enable the USB Interrupt */
NVIC_EnableIRQ(USB_IRQn); /* enable USB interrupt */
// NVIC_SetPriority (USB_IRQn, 0); /* highest priority */
PRINT_Log("Host Initialized\r\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 */
//PRINT_Log("In USB_IRQHandler().\r\n");
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)?\r\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)?\r\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 */
}
#ifdef TARGET_LPC2368
NVIC->Address = 0;
#endif
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:\r\n");
while (!HOST_RhscIntr);
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)
; // 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) {
;
}
HOST_WdhIntr = 0;
}
/*
**************************************************************************************************************
* READ LE 32U
*
* Description: This function is used to read an unsigned integer from a charecter buffer in the platform
* containing little endian processor
*
* Arguments : pmem Pointer to the charecter buffer
*
* Returns : val Unsigned integer
*
**************************************************************************************************************
*/
USB_INT32U ReadLE32U (volatile USB_INT08U *pmem)
{
USB_INT32U val;
((USB_INT08U *)&val)[0] = pmem[0];
((USB_INT08U *)&val)[1] = pmem[1];
((USB_INT08U *)&val)[2] = pmem[2];
((USB_INT08U *)&val)[3] = pmem[3];
return (val);
}
/*
**************************************************************************************************************
* 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)
{
pmem[0] = ((USB_INT08U *)&val)[0];
pmem[1] = ((USB_INT08U *)&val)[1];
pmem[2] = ((USB_INT08U *)&val)[2];
pmem[3] = ((USB_INT08U *)&val)[3];
}
/*
**************************************************************************************************************
* 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_INT08U *)&val)[0] = pmem[0];
((USB_INT08U *)&val)[1] = pmem[1];
return (val);
}
/*
**************************************************************************************************************
* 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)
{
pmem[0] = ((USB_INT08U *)&val)[0];
pmem[1] = ((USB_INT08U *)&val)[1];
}
/*
**************************************************************************************************************
* 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_INT08U *)&val)[0] = pmem[3];
((USB_INT08U *)&val)[1] = pmem[2];
((USB_INT08U *)&val)[2] = pmem[1];
((USB_INT08U *)&val)[3] = pmem[0];
return (val);
}
/*
**************************************************************************************************************
* 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)
{
pmem[0] = ((USB_INT08U *)&val)[3];
pmem[1] = ((USB_INT08U *)&val)[2];
pmem[2] = ((USB_INT08U *)&val)[1];
pmem[3] = ((USB_INT08U *)&val)[0];
}
/*
**************************************************************************************************************
* 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_INT08U *)&val)[0] = pmem[1];
((USB_INT08U *)&val)[1] = pmem[0];
return (val);
}
/*
**************************************************************************************************************
* 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)
{
pmem[0] = ((USB_INT08U *)&val)[1];
pmem[1] = ((USB_INT08U *)&val)[0];
}