ax88796dev.c

一个AVR 上的UIP移植程序

/*****************************************************************************
*  Module Name:       Realtek 8019AS Driver Interface for uIP-AVR Port
*  
*  Created By:        Louis Beaudoin (www.embedded-creations.com)
*
*  Original Release:  September 21, 2002 
*
*  Module Description:  
*  Provides three functions to interface with the Realtek 8019AS driver
*  These functions can be called directly from the main uIP control loop
*  to send packets from uip_buf and uip_appbuf, and store incoming packets to
*  uip_buf
*
*  September 30, 2002 - Louis Beaudoin
*    Modifications required to handle the packet receive function changes in
*      rtl8019.c.  There is no longer a need to poll for an empty buffer or
*      an overflow.
*    Added support for the Imagecraft Compiler
*
*****************************************************************************/

#include "ax88796dev.h"


#define IP_TCP_HEADER_LENGTH 40
#define TOTAL_HEADER_LENGTH (IP_TCP_HEADER_LENGTH+ETHERNET_HEADER_LENGTH)



void ax88796devInit(void)
{
	ax88796Init();
}


void ax88796devSend(void)
{
	ax88796BeginPacketSend(uip_len);
	
	// send packet, using data in uip_appdata if over the IP+TCP header size
	if( uip_len <= TOTAL_HEADER_LENGTH )
	{
		ax88796SendPacketData(uip_buf, uip_len);
	}
	else
	{
		uip_len -= TOTAL_HEADER_LENGTH;
		ax88796SendPacketData(uip_buf, TOTAL_HEADER_LENGTH);
		ax88796SendPacketData((unsigned char *)uip_appdata, uip_len);
	}

	ax88796EndPacketSend();
}



#if UIP_BUFSIZE > 255
unsigned int ax88796devPoll(void)
#else 
unsigned char ax88796devPoll(void)
#endif /* UIP_BUFSIZE > 255 */
{
	unsigned int packetLength;
	
	packetLength = ax88796BeginPacketRetreive();

	// if there's no packet or an error - exit without ending the operation
	if( !packetLength )
	{
		return 0;
	}

	// drop anything too big for the buffer
	if( packetLength > UIP_BUFSIZE )
	{
		ax88796EndPacketRetreive();
		return 0;
	}
	
	// copy the packet data into the uIP packet buffer
	ax88796RetreivePacketData( uip_buf, packetLength );
	ax88796EndPacketRetreive();
		
#if UIP_BUFSIZE > 255
	return packetLength;
#else 
	return (unsigned char)packetLength;
#endif /* UIP_BUFSIZE > 255 */
		
}