uart.cpp

USBN9603的DEMO程序

/*----------------------------------------------------------------------------
 *  Copyright (c) 2001 by National Semiconductor Corporation
 *  National Semiconductor Corporation
 *  2900 Semiconductor Drive
 *  Santa Clara, California 95051
 *
 *  All rights reserved
 *
 *<<<-------------------------------------------------------------------------
 * File Contents:
 *	Uart.cpp - Overlapped serial IO communication class.
 *
 *  Project: USB Demo Application
 *  Author : Yan Nosovitsky
 *  Date   : Dec 2001
 *----------------------------------------------------------------------->>>*/

#include "stdafx.h"
#include "Uart.h"



Uart::Uart()
{ 
	uartHandle = 0; 
}


BOOL Uart::OpenUART(LPCSTR lpszPortNum, DWORD  dwBaudRate, BYTE   byParity, BYTE   byStopBits, BYTE   byByteSize)
{
	DCB  dcb; // structure that defines the control setting for a serial communications device
	
	uartHandle = CreateFile(lpszPortNum, GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING,         
		FILE_ATTRIBUTE_NORMAL | FILE_FLAG_WRITE_THROUGH| FILE_FLAG_OVERLAPPED, NULL);                 // hTemplate must be NULL for comm devices 

	if ( uartHandle == INVALID_HANDLE_VALUE ) 
		return FALSE;

	PurgeComm(uartHandle,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);

	if ( !GetCommState(uartHandle, &dcb) ) 
	{
		CloseUART();
		return FALSE;
	}

	dcb.BaudRate = dwBaudRate;
	dcb.ByteSize = byByteSize;
	dcb.Parity   = byParity;
	dcb.StopBits = byStopBits;
	COMMTIMEOUTS  CommTimeouts;
    BOOL bRetVal;

    bRetVal = GetCommTimeouts(uartHandle, &CommTimeouts);
    if(bRetVal) 
	{
        CommTimeouts.ReadIntervalTimeout = 0;
        CommTimeouts.ReadTotalTimeoutMultiplier = 0;
        CommTimeouts.ReadTotalTimeoutConstant = 1;
        bRetVal = SetCommTimeouts(uartHandle, &CommTimeouts);
    }

	if ( ! SetCommState(uartHandle, &dcb) ) 
	{
		CloseUART();
		return FALSE;
	}

    //
    // set comm buffer sizes
    //
    SetupComm(uartHandle, 1024, 1024);


	return TRUE;
}


void Uart::CloseUART()
{

	if ( uartHandle > 0 )
	{
		PurgeComm(uartHandle,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
		CloseHandle(uartHandle);
	}

	uartHandle = 0; 
}


bool Uart::WriteData(BYTE* pdata, DWORD   len)
{
	DWORD written = 0;
	OVERLAPPED  m_ov;

	if ( len < 1 )
		return FALSE;

	memset( &m_ov, 0, sizeof( OVERLAPPED ) ) ;
	// create event for overlapped I/O
	m_ov.hEvent = CreateEvent(NULL, FALSE, FALSE, "");    // pointer to event-object name 

	if ( m_ov.hEvent == INVALID_HANDLE_VALUE )
		return FALSE;


	WriteFile(uartHandle,  pdata, len, &written, &m_ov);

	if ( ! GetOverlappedResult(uartHandle, &m_ov, &written, TRUE) )
	{
		CloseHandle(m_ov.hEvent);
		return FALSE;
	}

   CloseHandle(m_ov.hEvent);

   COMSTAT     ComStat;
   DWORD	dwErrorFlags;
   ClearCommError( uartHandle, &dwErrorFlags, &ComStat );

	return TRUE;
}



DWORD Uart::ReadData(BYTE* pdest, DWORD  len, DWORD  dwMaxWait)
{

	DWORD		result = 0;
	DWORD		read   = 0; // num read bytes
	DWORD	    mask   = 0; // a 32-bit variable that receives a mask indicating the type of event that occurred
	DWORD		dwCommErrors = 0;
	OVERLAPPED  m_ov;

	DWORD		i;
	COMSTAT ComStat;
   
	memset( &m_ov, 0, sizeof( OVERLAPPED ) ) ;

	if ( len < 1 ) return(0);

	// create event for overlapped I/O

	m_ov.hEvent = CreateEvent(NULL, FALSE, FALSE, ""); 

	if ( m_ov.hEvent == INVALID_HANDLE_VALUE )
		return -1;

	for (i = 0; i < dwMaxWait; i += 5)
	{
		Sleep(5);
		ClearCommError(uartHandle, &dwCommErrors, &ComStat);
		if (ComStat.cbInQue > 0)
		{
			if (!ReadFile(uartHandle,	pdest, len, &read, &m_ov))
			{
				ClearCommError(uartHandle, &dwCommErrors, NULL);
				CloseHandle(m_ov.hEvent);
				return -1;
			}
			CloseHandle(m_ov.hEvent);
			return read;
		}
	}

	CloseHandle(m_ov.hEvent);
	
	return -1;
}


BOOL Uart::IsNT(VOID)
{
    OSVERSIONINFO osvi;
    
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    
    GetVersionEx(&osvi);

    if (osvi.dwPlatformId == VER_PLATFORM_WIN32_NT) 
    {
        return TRUE;
    }
    else
    {
        return FALSE;
    }
}