谢谢!~~~能看看接收的程序么??
麻烦您了!~~我想问问它在程序中起什么用!~~为什么用CURR==0,来判断硬件是否读错??RETURN又是什么功能呢???谢谢!~~~~~
//------------------------------------------------------------------------
// This functions checks the 8019 receive event status
// word to see if an ethernet frame has arrived. If so,
// set EVENT_ETH_ARRIVED bit in global event_word
//------------------------------------------------------------------------
void query_8019(void)
{
char bnry,curr;
page(0);
bnry=reg03; //bnry page have read 读页指针
page(1);
curr=reg07; //curr writepoint 8019写页指针
page(0);
if ((curr==0)) return ;//
bnry=bnry++;
if (bnry> 0x7f) bnry=0x4c;
if (bnry!=curr) //此时表示有新的数据包在缓冲区里
{
EA = 0;
event_word |= EVENT_ETH_ARRIVED;
EA = 1;
}
reg0b=0x00; reg0a=0x00; reg00=0x22;//complete dma page 0
}
发表时间:2003年5月10日16:45:21