x10
Post By：2005-11-7 16:14:00 [只看该作者]
在使用USB的文件操作之前可调用下面函数检查USB是否存在。
unsigned int PortBaseAddr = 0x300;
// return = 1: USB is online
// = 0: USB is not found!
int IsUSBOnline( )
{
unsigned char ub1;
outportb( PortBaseAddr + 1, 0x0a );
outportb( PortBaseAddr, 0x20 );
ub1 = inportb( PortBaseAddr );
if( ub1 & 0x20 ) return 1;
return 0;
}
unsigned int PortBaseAddr = 0x300;
// return = 1: USB is online
// = 0: USB is not found!
int IsUSBOnline( )
{
unsigned char ub1;
outportb( PortBaseAddr + 1, 0x0a );
outportb( PortBaseAddr, 0x20 );
ub1 = inportb( PortBaseAddr );
if( ub1 & 0x20 ) return 1;
return 0;
}
