Demo/ColdFire_MCF52233_Eclipse/RTOSDemo/webserver/FEC.c

/*
	FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org is free software; you can redistribute it and/or modify it 
	under the terms of the GNU General Public License (version 2) as published
	by the Free Software Foundation and modified by the FreeRTOS exception.

	FreeRTOS.org is distributed in the hope that it will be useful,	but WITHOUT
	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
	FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 
	more details.

	You should have received a copy of the GNU General Public License along 
	with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 
	Temple Place, Suite 330, Boston, MA  02111-1307  USA.

	A special exception to the GPL is included to allow you to distribute a 
	combined work that includes FreeRTOS.org without being obliged to provide
	the source code for any proprietary components.  See the licensing section
	of http://www.FreeRTOS.org for full details.


	***************************************************************************
	*                                                                         *
	* Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *
	*                                                                         *
	* This is a concise, step by step, 'hands on' guide that describes both   *
	* general multitasking concepts and FreeRTOS specifics. It presents and   *
	* explains numerous examples that are written using the FreeRTOS API.     *
	* Full source code for all the examples is provided in an accompanying    *
	* .zip file.                                                              *
	*                                                                         *
	***************************************************************************

	1 tab == 4 spaces!

	Please ensure to read the configuration and relevant port sections of the
	online documentation.

	http://www.FreeRTOS.org - Documentation, latest information, license and
	contact details.

	http://www.SafeRTOS.com - A version that is certified for use in safety
	critical systems.

	http://www.OpenRTOS.com - Commercial support, development, porting,
	licensing and training services.
*/

/* Kernel includes. */
#include "FreeRTOS.h"
#include "semphr.h"
#include "task.h"

/* Hardware includes. */
#include "fecbd.h"
#include "mii.h"
#include "eth_phy.h"
#include "eth.h"

/* uIP includes. */
#include "uip.h"
#include "uip_arp.h"

/* Delay between polling the PHY to see if a link has been established. */
#define fecLINK_DELAY							( 500 / portTICK_RATE_MS )

/* Delay to wait for an MII access. */
#define fecMII_DELAY							( 10 / portTICK_RATE_MS )
#define fecMAX_POLLS							( 20 )

/* Constants used to delay while waiting for a tx descriptor to be free. */
#define fecMAX_WAIT_FOR_TX_BUFFER						( 200 / portTICK_RATE_MS )

/* We only use a single Tx descriptor which can lead to Txed packets being sent
twice (due to a bug in the FEC silicon).  However, in this case the bug is used
to our advantage in that it means the uip-split mechanism is not required. */
#define fecNUM_FEC_TX_BUFFERS					( 1 )
#define fecTX_BUFFER_TO_USE						( 0 )
/*-----------------------------------------------------------*/

/* The semaphore used to wake the uIP task when data arrives. */
xSemaphoreHandle xFECSemaphore = NULL, xTxSemaphore = NULL;

/* The buffer used by the uIP stack.  In this case the pointer is used to
point to one of the Rx buffers to effect a zero copy policy. */
unsigned portCHAR *uip_buf;

/* The DMA descriptors.  This is a char array to allow us to align it correctly. */
static unsigned portCHAR xFECTxDescriptors_unaligned[ ( fecNUM_FEC_TX_BUFFERS * sizeof( FECBD ) ) + 16 ];
static unsigned portCHAR xFECRxDescriptors_unaligned[ ( configNUM_FEC_RX_BUFFERS * sizeof( FECBD ) ) + 16 ];
static FECBD *xFECTxDescriptors;
static FECBD *xFECRxDescriptors;

/* The DMA buffers.  These are char arrays to allow them to be aligned correctly. */
static unsigned portCHAR ucFECRxBuffers[ ( configNUM_FEC_RX_BUFFERS * configFEC_BUFFER_SIZE ) + 16 ];
static unsigned portBASE_TYPE uxNextRxBuffer = 0, uxIndexToBufferOwner = 0;

/*-----------------------------------------------------------*/

/*
 * Enable all the required interrupts in the FEC and in the interrupt controller.
 */
static void prvEnableFECInterrupts( void );

/*
 * Reset the FEC if we get into an unrecoverable state.
 */
static void prvResetFEC( portBASE_TYPE xCalledFromISR );

/********************************************************************/

/*
 * FUNCTION ADAPTED FROM FREESCALE SUPPLIED SOURCE
 *
 * Write a value to a PHY's MII register.
 *
 * Parameters:
 *  ch          FEC channel
 *  phy_addr    Address of the PHY.
 *  reg_addr    Address of the register in the PHY.
 *  data        Data to be written to the PHY register.
 *
 * Return Values:
 *  0 on failure
 *  1 on success.
 *
 * Please refer to your PHY manual for registers and their meanings.
 * mii_write() polls for the FEC's MII interrupt event and clears it.
 * If after a suitable amount of time the event isn't triggered, a
 * value of 0 is returned.
 */
static int fec_mii_write( int phy_addr, int reg_addr, int data )
{
int timeout, iReturn;
uint32 eimr;

    /* Clear the MII interrupt bit */
    MCF_FEC_EIR = MCF_FEC_EIR_MII;

    /* Mask the MII interrupt */
    eimr = MCF_FEC_EIMR;
    MCF_FEC_EIMR &= ~MCF_FEC_EIMR_MII;

    /* Write to the MII Management Frame Register to kick-off the MII write */
    MCF_FEC_MMFR = MCF_FEC_MMFR_ST_01 | MCF_FEC_MMFR_OP_WRITE | MCF_FEC_MMFR_PA(phy_addr) | MCF_FEC_MMFR_RA(reg_addr) | MCF_FEC_MMFR_TA_10 | MCF_FEC_MMFR_DATA( data );

    /* Poll for the MII interrupt (interrupt should be masked) */
    for( timeout = 0; timeout < fecMAX_POLLS; timeout++ )
    {
        if( MCF_FEC_EIR & MCF_FEC_EIR_MII )
        {
			break;
        }
        else
        {
        	vTaskDelay( fecMII_DELAY );
        }
    }

    if( timeout == fecMAX_POLLS )
    {
        iReturn = 0;
    }
    else
    {
		iReturn = 1;
    }

	/* Clear the MII interrupt bit */
	MCF_FEC_EIR = MCF_FEC_EIR_MII;

	/* Restore the EIMR */
	MCF_FEC_EIMR = eimr;

    return iReturn;
}

/********************************************************************/
/*
 * FUNCTION ADAPTED FROM FREESCALE SUPPLIED SOURCE
 *
 * Read a value from a PHY's MII register.
 *
 * Parameters:
 *  ch          FEC channel
 *  phy_addr    Address of the PHY.
 *  reg_addr    Address of the register in the PHY.
 *  data        Pointer to storage for the Data to be read
 *              from the PHY register (passed by reference)
 *
 * Return Values:
 *  0 on failure
 *  1 on success.
 *
 * Please refer to your PHY manual for registers and their meanings.
 * mii_read() polls for the FEC's MII interrupt event and clears it.
 * If after a suitable amount of time the event isn't triggered, a
 * value of 0 is returned.
 */
static int fec_mii_read( int phy_addr, int reg_addr, unsigned portSHORT* data )
{
int timeout, iReturn;
uint32 eimr;

    /* Clear the MII interrupt bit */
    MCF_FEC_EIR = MCF_FEC_EIR_MII;

    /* Mask the MII interrupt */
    eimr = MCF_FEC_EIMR;
    MCF_FEC_EIMR &= ~MCF_FEC_EIMR_MII;

    /* Write to the MII Management Frame Register to kick-off the MII read */
    MCF_FEC_MMFR = MCF_FEC_MMFR_ST_01 | MCF_FEC_MMFR_OP_READ | MCF_FEC_MMFR_PA(phy_addr) | MCF_FEC_MMFR_RA(reg_addr) | MCF_FEC_MMFR_TA_10;

    /* Poll for the MII interrupt (interrupt should be masked) */
    for( timeout = 0; timeout < fecMAX_POLLS; timeout++ )
    {
        if (MCF_FEC_EIR & MCF_FEC_EIR_MII)
        {
            break;
        }
        else
        {
        	vTaskDelay( fecMII_DELAY );
        }
    }

    if( timeout == fecMAX_POLLS )
    {
        iReturn = 0;
    }
    else
    {
		*data = (uint16)(MCF_FEC_MMFR & 0x0000FFFF);
		iReturn = 1;
    }

	/* Clear the MII interrupt bit */
	MCF_FEC_EIR = MCF_FEC_EIR_MII;

	/* Restore the EIMR */
	MCF_FEC_EIMR = eimr;

    return iReturn;
}


/********************************************************************/
/*
 * FUNCTION ADAPTED FROM FREESCALE SUPPLIED SOURCE
 *
 * Generate the hash table settings for the given address
 *
 * Parameters:
 *  addr    48-bit (6 byte) Address to generate the hash for
 *
 * Return Value:
 *  The 6 most significant bits of the 32-bit CRC result
 */
static unsigned portCHAR fec_hash_address( const unsigned portCHAR* addr )
{
unsigned portLONG crc;
unsigned portCHAR byte;
int i, j;

	crc = 0xFFFFFFFF;
	for(i=0; i<6; ++i)
	{
		byte = addr[i];
		for(j=0; j<8; ++j)
		{
			if((byte & 0x01)^(crc & 0x01))
			{
				crc >>= 1;
				crc = crc ^ 0xEDB88320;
			}
			else
			{
				crc >>= 1;
			}

			byte >>= 1;
		}
	}

	return (unsigned portCHAR)(crc >> 26);
}

/********************************************************************/
/*
 * FUNCTION ADAPTED FROM FREESCALE SUPPLIED SOURCE
 *
 * Set the Physical (Hardware) Address and the Individual Address
 * Hash in the selected FEC
 *
 * Parameters:
 *  ch  FEC channel
 *  pa  Physical (Hardware) Address for the selected FEC
 */
static void fec_set_address( const unsigned portCHAR *pa )
{
	unsigned portCHAR crc;

	/*
	* Set the Physical Address
	*/
	/* Set the source address for the controller */
	MCF_FEC_PALR = ( pa[ 0 ] << 24 ) | ( pa[ 1 ] << 16 ) | ( pa[ 2 ] << 8 ) | ( pa[ 3 ] << 0 );
	MCF_FEC_PAUR = ( pa[ 4 ] << 24 ) | ( pa[ 5 ] << 16 );

	/*
	* Calculate and set the hash for given Physical Address
	* in the  Individual Address Hash registers
	*/
	crc = fec_hash_address( pa );
	if( crc >= 32 )
	{
		MCF_FEC_IAUR |= (unsigned portLONG)(1 << (crc - 32));
	}
	else
	{
		MCF_FEC_IALR |= (unsigned portLONG)(1 << crc);
	}
}
/*-----------------------------------------------------------*/

static void prvInitialiseFECBuffers( void )
{
unsigned portBASE_TYPE ux;
unsigned portCHAR *pcBufPointer;

	/* Correctly align the Tx descriptor pointer. */
	pcBufPointer = &( xFECTxDescriptors_unaligned[ 0 ] );
	while( ( ( unsigned portLONG ) pcBufPointer & 0x0fUL ) != 0 )
	{
		pcBufPointer++;
	}

	xFECTxDescriptors = ( FECBD * ) pcBufPointer;

	/* Likewise the Rx descriptor pointer. */
	pcBufPointer = &( xFECRxDescriptors_unaligned[ 0 ] );
	while( ( ( unsigned portLONG ) pcBufPointer & 0x0fUL ) != 0 )
	{
		pcBufPointer++;
	}

	xFECRxDescriptors = ( FECBD * ) pcBufPointer;


	/* Setup the Tx buffers and descriptors.  There is no separate Tx buffer
	to point to (the Rx buffers are actually used) so the data member is
	set to NULL for now. */
	for( ux = 0; ux < fecNUM_FEC_TX_BUFFERS; ux++ )
	{
		xFECTxDescriptors[ ux ].status = TX_BD_TC;
		xFECTxDescriptors[ ux ].data = NULL;
		xFECTxDescriptors[ ux ].length = 0;
	}

	/* Setup the Rx buffers and descriptors, having first ensured correct
	alignment. */
	pcBufPointer = &( ucFECRxBuffers[ 0 ] );
	while( ( ( unsigned portLONG ) pcBufPointer & 0x0fUL ) != 0 )
	{
		pcBufPointer++;
	}

	for( ux = 0; ux < configNUM_FEC_RX_BUFFERS; ux++ )
	{
	    xFECRxDescriptors[ ux ].status = RX_BD_E;
	    xFECRxDescriptors[ ux ].length = configFEC_BUFFER_SIZE;
	    xFECRxDescriptors[ ux ].data = pcBufPointer;
	    pcBufPointer += configFEC_BUFFER_SIZE;
	}

	/* Set the wrap bit in the last descriptors to form a ring. */
	xFECTxDescriptors[ fecNUM_FEC_TX_BUFFERS - 1 ].status |= TX_BD_W;
	xFECRxDescriptors[ configNUM_FEC_RX_BUFFERS - 1 ].status |= RX_BD_W;

	uxNextRxBuffer = 0;
}
/*-----------------------------------------------------------*/

void vFECInit( void )
{
unsigned portSHORT usData;
struct uip_eth_addr xAddr;
unsigned portBASE_TYPE ux;

/* The MAC address is set at the foot of FreeRTOSConfig.h. */
const unsigned portCHAR ucMACAddress[6] =
{
	configMAC_0, configMAC_1,configMAC_2, configMAC_3, configMAC_4, configMAC_5
};

	/* Create the semaphore used by the ISR to wake the uIP task. */
	vSemaphoreCreateBinary( xFECSemaphore );

	/* Create the semaphore used to unblock any tasks that might be waiting
	for a Tx descriptor. */
	vSemaphoreCreateBinary( xTxSemaphore );

	/* Initialise all the buffers and descriptors used by the DMA. */
	prvInitialiseFECBuffers();

	for( usData = 0; usData < 6; usData++ )
	{
		xAddr.addr[ usData ] = ucMACAddress[ usData ];
	}
	uip_setethaddr( xAddr );

	/* Set the Reset bit and clear the Enable bit */
	MCF_FEC_ECR = MCF_FEC_ECR_RESET;

	/* Wait at least 8 clock cycles */
	for( usData = 0; usData < 10; usData++ )
	{
		asm( "NOP" );
	}

	/* Set MII speed to 2.5MHz. */
	MCF_FEC_MSCR = MCF_FEC_MSCR_MII_SPEED( ( ( ( configCPU_CLOCK_HZ / 1000000 ) / 5 ) + 1 ) );

	/* Initialize PLDPAR to enable Ethernet LEDs. */
	MCF_GPIO_PLDPAR =  MCF_GPIO_PLDPAR_ACTLED_ACTLED | MCF_GPIO_PLDPAR_LINKLED_LINKLED | MCF_GPIO_PLDPAR_SPDLED_SPDLED
					 | MCF_GPIO_PLDPAR_DUPLED_DUPLED | MCF_GPIO_PLDPAR_COLLED_COLLED | MCF_GPIO_PLDPAR_RXLED_RXLED
					 | MCF_GPIO_PLDPAR_TXLED_TXLED;

	/* Initialize Port TA to enable Axcel control. */
	MCF_GPIO_PTAPAR = 0x00;
	MCF_GPIO_DDRTA  = 0x0F;
	MCF_GPIO_PORTTA = 0x04;

	/* Set phy address to zero. */
	MCF_EPHY_EPHYCTL1 = MCF_EPHY_EPHYCTL1_PHYADD( 0 );

	/* Enable EPHY module with PHY clocks disabled.  Do not turn on PHY clocks
	until both FEC and EPHY are completely setup (see Below). */
	MCF_EPHY_EPHYCTL0 = (uint8)(MCF_EPHY_EPHYCTL0_DIS100 | MCF_EPHY_EPHYCTL0_DIS10);

	/* Enable auto_neg at start-up */
	MCF_EPHY_EPHYCTL0 = (uint8)(MCF_EPHY_EPHYCTL0 & (MCF_EPHY_EPHYCTL0_ANDIS));

	/* Enable EPHY module. */
	MCF_EPHY_EPHYCTL0 = (uint8)(MCF_EPHY_EPHYCTL0_EPHYEN | MCF_EPHY_EPHYCTL0);

	/* Let PHY PLLs be determined by PHY. */
	MCF_EPHY_EPHYCTL0 = (uint8)(MCF_EPHY_EPHYCTL0  & ~(MCF_EPHY_EPHYCTL0_DIS100 | MCF_EPHY_EPHYCTL0_DIS10));

	/* Settle. */
	vTaskDelay( fecLINK_DELAY );

	/* Can we talk to the PHY? */
	do
	{
		vTaskDelay( fecLINK_DELAY );
		usData = 0;
		fec_mii_read( configPHY_ADDRESS, PHY_PHYIDR1, &usData );

	} while( usData == 0xffff );

	do
	{
		/* Start auto negotiate. */
		fec_mii_write( configPHY_ADDRESS, PHY_BMCR, ( PHY_BMCR_AN_RESTART | PHY_BMCR_AN_ENABLE ) );

		/* Wait for auto negotiate to complete. */
		do
		{
			ux++;
			if( ux > 10 )
			{
				/* Hardware bug workaround!  Force 100Mbps half duplex. */
				while( !fec_mii_read( configPHY_ADDRESS, 0, &usData ) ){};
				usData &= ~0x2000;							/* 10Mbps */
				usData &= ~0x0100;							/* Half Duplex */
				usData &= ~0x1000;							/* Manual Mode */
				while( !fec_mii_write( configPHY_ADDRESS, 0, usData ) ){};
				while( !fec_mii_write( configPHY_ADDRESS, 0, (usData|0x0200) )){}; /* Force re-negotiate */
				break;
			}
			vTaskDelay( fecLINK_DELAY );
			fec_mii_read( configPHY_ADDRESS, PHY_BMSR, &usData );

		} while( !( usData & PHY_BMSR_AN_COMPLETE ) );

	} while( 0 ); //while( !( usData & PHY_BMSR_LINK ) );

	/* When we get here we have a link - find out what has been negotiated. */
	fec_mii_read( configPHY_ADDRESS, PHY_ANLPAR, &usData );

	if( ( usData & PHY_ANLPAR_100BTX_FDX ) || ( usData & PHY_ANLPAR_100BTX ) )
	{
		/* Speed is 100. */
	}
	else
	{
		/* Speed is 10. */
	}

	if( ( usData & PHY_ANLPAR_100BTX_FDX ) || ( usData & PHY_ANLPAR_10BTX_FDX ) )
	{
		MCF_FEC_RCR &= (unsigned portLONG)~MCF_FEC_RCR_DRT;
		MCF_FEC_TCR |= MCF_FEC_TCR_FDEN;
	}
	else
	{
		MCF_FEC_RCR |= MCF_FEC_RCR_DRT;
		MCF_FEC_TCR &= (unsigned portLONG)~MCF_FEC_TCR_FDEN;
	}

	/* Clear the Individual and Group Address Hash registers */
	MCF_FEC_IALR = 0;
	MCF_FEC_IAUR = 0;
	MCF_FEC_GALR = 0;
	MCF_FEC_GAUR = 0;

	/* Set the Physical Address for the selected FEC */
	fec_set_address( ucMACAddress );

	/* Set Rx Buffer Size */
	MCF_FEC_EMRBR = (unsigned portSHORT)configFEC_BUFFER_SIZE;

	/* Point to the start of the circular Rx buffer descriptor queue */
	MCF_FEC_ERDSR = ( volatile unsigned portLONG ) &( xFECRxDescriptors[ 0 ] );

	/* Point to the start of the circular Tx buffer descriptor queue */
	MCF_FEC_ETSDR = ( volatile unsigned portLONG ) &( xFECTxDescriptors[ 0 ] );

	/* Mask all FEC interrupts */
	MCF_FEC_EIMR = ( unsigned portLONG ) -1;

	/* Clear all FEC interrupt events */
	MCF_FEC_EIR = ( unsigned portLONG ) -1;

	/* Initialize the Receive Control Register */
	MCF_FEC_RCR = MCF_FEC_RCR_MAX_FL(ETH_MAX_FRM) | MCF_FEC_RCR_FCE;

	MCF_FEC_RCR |= MCF_FEC_RCR_MII_MODE;

	#if( configUSE_PROMISCUOUS_MODE == 1 )
	{
		MCF_FEC_RCR |= MCF_FEC_RCR_PROM;
	}
	#endif

	prvEnableFECInterrupts();

	/* Finally... enable. */
	MCF_FEC_ECR = MCF_FEC_ECR_ETHER_EN;
	MCF_FEC_RDAR = MCF_FEC_RDAR_R_DES_ACTIVE;
}
/*-----------------------------------------------------------*/

static void prvEnableFECInterrupts( void )
{
const unsigned portBASE_TYPE uxFirstFECVector = 23, uxLastFECVector = 35;
unsigned portBASE_TYPE ux;

#if configFEC_INTERRUPT_PRIORITY > configMAX_SYSCALL_INTERRUPT_PRIORITY
	#error configFEC_INTERRUPT_PRIORITY must be less than or equal to configMAX_SYSCALL_INTERRUPT_PRIORITY
#endif

	/* Set the priority of each of the FEC interrupts. */
	for( ux = uxFirstFECVector; ux <= uxLastFECVector; ux++ )
	{
		MCF_INTC0_ICR( ux ) = MCF_INTC_ICR_IL( configFEC_INTERRUPT_PRIORITY );
	}

	/* Enable the FEC interrupts in the mask register */
	MCF_INTC0_IMRH &= ~( MCF_INTC_IMRH_INT_MASK33 | MCF_INTC_IMRH_INT_MASK34 | MCF_INTC_IMRH_INT_MASK35 );
	MCF_INTC0_IMRL &= ~( MCF_INTC_IMRL_INT_MASK25 | MCF_INTC_IMRL_INT_MASK26 | MCF_INTC_IMRL_INT_MASK27
						| MCF_INTC_IMRL_INT_MASK28 | MCF_INTC_IMRL_INT_MASK29 | MCF_INTC_IMRL_INT_MASK30
						| MCF_INTC_IMRL_INT_MASK31 | MCF_INTC_IMRL_INT_MASK23 | MCF_INTC_IMRL_INT_MASK24
						| MCF_INTC_IMRL_MASKALL );

	/* Clear any pending FEC interrupt events */
	MCF_FEC_EIR = MCF_FEC_EIR_CLEAR_ALL;

	/* Unmask all FEC interrupts */
	MCF_FEC_EIMR = MCF_FEC_EIMR_UNMASK_ALL;
}
/*-----------------------------------------------------------*/

static void prvResetFEC( portBASE_TYPE xCalledFromISR )
{
portBASE_TYPE x;

	/* A critical section is used unless this function is being called from
	an ISR. */
	if( xCalledFromISR == pdFALSE )
	{
		taskENTER_CRITICAL();
	}

	{
		/* Reset all buffers and descriptors. */
		prvInitialiseFECBuffers();

		/* Set the Reset bit and clear the Enable bit */
		MCF_FEC_ECR = MCF_FEC_ECR_RESET;

		/* Wait at least 8 clock cycles */
		for( x = 0; x < 10; x++ )
		{
			asm( "NOP" );
		}

		/* Re-enable. */
		MCF_FEC_ECR = MCF_FEC_ECR_ETHER_EN;
		MCF_FEC_RDAR = MCF_FEC_RDAR_R_DES_ACTIVE;
	}

	if( xCalledFromISR == pdFALSE )
	{
		taskEXIT_CRITICAL();
	}
}
/*-----------------------------------------------------------*/

unsigned short usFECGetRxedData( void )
{
unsigned portSHORT usLen;

	/* Obtain the size of the packet and put it into the "len" variable. */
	usLen = xFECRxDescriptors[ uxNextRxBuffer ].length;

	if( ( usLen != 0 ) && ( ( xFECRxDescriptors[ uxNextRxBuffer ].status & RX_BD_E ) == 0 ) )
	{
		uip_buf = xFECRxDescriptors[ uxNextRxBuffer ].data;
	}
	else
	{
		usLen = 0;
	}

	return usLen;
}
/*-----------------------------------------------------------*/

void vFECRxProcessingCompleted( void )
{
	/* Free the descriptor as the buffer it points to is no longer in use. */
	xFECRxDescriptors[ uxNextRxBuffer ].status |= RX_BD_E;
	MCF_FEC_RDAR = MCF_FEC_RDAR_R_DES_ACTIVE;
	uxNextRxBuffer++;
	if( uxNextRxBuffer >= configNUM_FEC_RX_BUFFERS )
	{
		uxNextRxBuffer = 0;
	}
}
/*-----------------------------------------------------------*/

void vFECSendData( void )
{
	/* Ensure no Tx frames are outstanding. */
	if( xSemaphoreTake( xTxSemaphore, fecMAX_WAIT_FOR_TX_BUFFER ) == pdPASS )
	{
		/* Get a DMA buffer into which we can write the data to send. */
		if( xFECTxDescriptors[ fecTX_BUFFER_TO_USE ].status & TX_BD_R )
		{
			/*** ERROR didn't expect this.  Sledge hammer error handling. ***/
			prvResetFEC( pdFALSE );

			/* Make sure we leave the semaphore in the expected state as nothing
			is being transmitted this will not happen in the Tx ISR. */
			xSemaphoreGive( xTxSemaphore );
		}
		else
		{
			/* Setup the buffer descriptor for transmission.  The data being
			sent is actually stored in one of the Rx descriptor buffers,
			pointed to by uip_buf. */
			xFECTxDescriptors[ fecTX_BUFFER_TO_USE ].length = uip_len;
			xFECTxDescriptors[ fecTX_BUFFER_TO_USE ].status |= ( TX_BD_R | TX_BD_L );
			xFECTxDescriptors[ fecTX_BUFFER_TO_USE ].data = uip_buf;

			/* Remember which Rx descriptor owns the buffer we are sending. */
			uxIndexToBufferOwner = uxNextRxBuffer;

			/* We have finished with this Rx descriptor now. */
			uxNextRxBuffer++;
			if( uxNextRxBuffer >= configNUM_FEC_RX_BUFFERS )
			{
				uxNextRxBuffer = 0;
			}

			/* Continue the Tx DMA (in case it was waiting for a new TxBD) */
			MCF_FEC_TDAR = MCF_FEC_TDAR_X_DES_ACTIVE;
		}
	}
	else
	{
		/* Gave up waiting.  Free the buffer back to the DMA. */
		vFECRxProcessingCompleted();
	}
}
/*-----------------------------------------------------------*/

void vFEC_ISR( void )
{
unsigned portLONG ulEvent;
portBASE_TYPE xHighPriorityTaskWoken = pdFALSE;

	/* This handler is called in response to any of the many separate FEC
	interrupt. */

	/* Find the cause of the interrupt, then clear the interrupt. */
	ulEvent = MCF_FEC_EIR & MCF_FEC_EIMR;
	MCF_FEC_EIR = ulEvent;

	if( ( ulEvent & MCF_FEC_EIR_RXB ) || ( ulEvent & MCF_FEC_EIR_RXF ) )
	{
		/* A packet has been received.  Wake the handler task. */
		xSemaphoreGiveFromISR( xFECSemaphore, &xHighPriorityTaskWoken );
	}

	if( ulEvent & ( MCF_FEC_EIR_UN | MCF_FEC_EIR_RL | MCF_FEC_EIR_LC | MCF_FEC_EIR_EBERR | MCF_FEC_EIR_BABT | MCF_FEC_EIR_BABR | MCF_FEC_EIR_HBERR ) )
	{
		/* Sledge hammer error handling. */
		prvResetFEC( pdTRUE );
	}

	if( ( ulEvent & MCF_FEC_EIR_TXF ) || ( ulEvent & MCF_FEC_EIR_TXB ) )
	{
		/* The buffer being sent is pointed to by an Rx descriptor, now the
		buffer has been sent we can mark the Rx descriptor as free again. */
		xFECRxDescriptors[ uxIndexToBufferOwner ].status |= RX_BD_E;
		MCF_FEC_RDAR = MCF_FEC_RDAR_R_DES_ACTIVE;
		xSemaphoreGiveFromISR( xTxSemaphore, &xHighPriorityTaskWoken );
	}

	portEND_SWITCHING_ISR( xHighPriorityTaskWoken );
}
/*-----------------------------------------------------------*/

/* Install the many different interrupt vectors, all of which call the same
handler function. */
void __attribute__ ((interrupt)) __cs3_isr_interrupt_87( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_88( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_89( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_90( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_91( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_92( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_93( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_94( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_95( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_96( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_97( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_98( void ) { vFEC_ISR(); }
void __attribute__ ((interrupt)) __cs3_isr_interrupt_99( void ) { vFEC_ISR(); }