串口中断

在VXD中初始化串口如下:(在dos下用TC是成功的)

void MyHwInt::OnHardwareInt(VMHANDLE hVM)
{
unsigned char i,j;
_outp(0x70,0xc);
_inp(0x71);
x++;
if(x>=1024)
{
//查询COM1口有无数据来
i=_inp(0x3fd);//查询状态寄存器
if((i&0x01)!=0)
{
j=_inp(0x3f8);//读出数据
*(pVal)=i;
//VSD_Bell();
}
else
*(pVal)=0x5555;
//
x=0;y++;
dprintf(\"y++\");
//VWIN32_QueueUserApc(CallBackApc,(DWORD)&y,TheThread);
VWIN32_PulseWin32Event(hEventRing0);
//VSD_Bell();
}

sendPhysicalEOI();
}

BOOL MbiDevice::OnSysDynamicDeviceInit()
{
pMyIRQ=new MyHwInt();
if (!pMyIRQ || !pMyIRQ->hook()) return FALSE;
_outp(0x70,0xb);
b=_inp(0x71);
_outp(0x70,0xb);
_outp(0x71,0x40 | b);//允许周期中断
//初始化COM1
_outp(0x3fb,(unsigned char)0x80);//DLAB=1
_outp(0x3f8,(unsigned char)0x0c);//LSB
_outp(0x3f9,(unsigned char)0x00);//MSB
_outp(0x3fb,(unsigned char)0x03);//8bits no parity 1 stop
_outp(0x3f9,(unsigned char)0x01);//open int
//

pMyIRQ->physicalUnmask();
return TRUE;
}
串口始终没被正确初始化,无数据收到,HY?

因此初始是以前程序搬来的且此法简单

为什么不用vcommport呢？