串口通信中读取COM3、4中的数据(急死!)

WilliamY2024 2000-09-06 12:07:00
各位大侠好:
我遇到一个非常棘手的问题。我们的项目中有一部分要求用TC++3.0
编写串口通信,我借用了CSDN上的serial.zip这个例子。但是由于工控机
上有4个串口,我现在无法读取COM3、4上的数据。急死!
我把我修改的下段源程序列出,有人说我是8259寄存器部分写错了,
我恳请高手能帮我指出来到底错在哪里。下面程序试图读取COM3数据,但
不成功:
(对不起,现在我只能给115分了,我真想给高手1000分!)
1 改过的Serial.h
/*---------------------------------------------------------------------*
FILENAME: SERIAL.H

Some definitions used by SERIAL.C

*--------------------------------------------------------------------*/

#define COM1 1
#define COM2 2
#define COM1BASE 0x3F8 /* Base port address for COM1 */
#define COM2BASE 0x2F8 /* Base port address for COM2 */

/*
The 8250 UART has 10 registers accessible through 7 port addresses.
Here are their addresses relative to COM1BASE and COM2BASE. Note
that the baud rate registers, (DLL) and (DLH) are active only when
the Divisor-Latch Access-Bit (DLAB) is on. The (DLAB) is bit 7 of
the (LCR).

o TXR Output data to the serial port.
o RXR Input data from the serial port.
o LCR Initialize the serial port.
o IER Controls interrupt generation.
o IIR Identifies interrupts.
o MCR Send contorl signals to the modem.
o LSR Monitor the status of the serial port.
o MSR Receive status of the modem.
o DLL Low byte of baud rate divisor.
o DHH High byte of baud rate divisor.
*/
#define TXR 0 /* Transmit register (WRITE) */
#define RXR 0 /* Receive register (READ) */
#define IER 1 /* Interrupt Enable */
#define IIR 2 /* Interrupt ID */
#define LCR 3 /* Line control */
#define MCR 4 /* Modem control */
#define LSR 5 /* Line Status */
#define MSR 6 /* Modem Status */
#define DLL 0 /* Divisor Latch Low */
#define DLH 1 /* Divisor latch High */


/*-------------------------------------------------------------------*
Bit values held in the Line Control Register (LCR).
bit meaning
--- -------
0-1 00=5 bits, 01=6 bits, 10=7 bits, 11=8 bits.
2 Stop bits.
3 0=parity off, 1=parity on.
4 0=parity odd, 1=parity even.
5 Sticky parity.
6 Set break.
7 Toggle port addresses.
*-------------------------------------------------------------------*/
#define NO_PARITY 0x00
#define EVEN_PARITY 0x18
#define ODD_PARITY 0x08



/*-------------------------------------------------------------------*
Bit values held in the Line Status Register (LSR).
bit meaning
--- -------
0 Data ready.
1 Overrun error - Data register overwritten.
2 Parity error - bad transmission.
3 Framing error - No stop bit was found.
4 Break detect - End to transmission requested.
5 Transmitter holding register is empty.
6 Transmitter shift register is empty.
7 Time out - off line.
*-------------------------------------------------------------------*/
#define RCVRDY 0x01
#define OVRERR 0x02
#define PRTYERR 0x04
#define FRMERR 0x08
#define BRKERR 0x10
#define XMTRDY 0x20
#define XMTRSR 0x40
#define TIMEOUT 0x80

/*-------------------------------------------------------------------*
Bit values held in the Modem Output Control Register (MCR).
bit meaning
--- -------
0 Data Terminal Ready. Computer ready to go.
1 Request To Send. Computer wants to send data.
2 auxillary output #1.
3 auxillary output #2.(Note: This bit must be
set to allow the communications card to send
interrupts to the system)
4 UART ouput looped back as input.
5-7 not used.
*------------------------------------------------------------------*/
#define DTR 0x01
#define RTS 0x02
#define MC_INT 0x08


/*------------------------------------------------------------------*
Bit values held in the Modem Input Status Register (MSR).
bit meaning
--- -------
0 delta Clear To Send.
1 delta Data Set Ready.
2 delta Ring Indicator.
3 delta Data Carrier Detect.
4 Clear To Send.
5 Data Set Ready.
6 Ring Indicator.
7 Data Carrier Detect.
*------------------------------------------------------------------*/
#define CTS 0x10
#define DSR 0x20


/*------------------------------------------------------------------*
Bit values held in the Interrupt Enable Register (IER).
bit meaning
--- -------
0 Interrupt when data received.
1 Interrupt when transmitter holding reg. empty.
2 Interrupt when data reception error.
3 Interrupt when change in modem status register.
4-7 Not used.
*------------------------------------------------------------------*/
#define RX_INT 0x01


/*------------------------------------------------------------------*
Bit values held in the Interrupt Identification Register (IIR).
bit meaning
--- -------
0 Interrupt pending
1-2 Interrupt ID code
00=Change in modem status register,
01=Transmitter holding register empty,
10=Data received,
11=reception error, or break encountered.
3-7 Not used.
*------------------------------------------------------------------*/
#define RX_ID 0x04
#define RX_MASK 0x07


/*
These are the port addresses of the 8259 Programmable Interrupt
Controller (PIC).
*/
//#define IMR 0x21 /* Interrupt Mask Register port */
//#define ICR 0x20 /* Interrupt Control Port */
//我改的
#define IMR 0xa1 /* Interrupt Mask Register port */
#define ICR 0xa0 /* Interrupt Control Port */



/*
An end of interrupt needs to be sent to the Control Port of
the 8259 when a hardware interrupt ends.
*/
//#define EOI 0x20 /* End Of Interrupt */
//我改的
#define EOI 0xa0 /* End Of Interrupt */

/*
The (IMR) tells the (PIC) to service an interrupt only if it
is not masked (FALSE).
*/
#define IRQ3 0xF7 /* COM2 */
#define IRQ4 0xEF /* COM1 */
//我加的
#define IRQ10 0xFB /* COM3 */
#define IRQ11 0xf7 /* COM4 */

class serial
{
int flag;
int SetSerial();
int SetOthers(int Parity, int Bits, int StopBit);
int SetSpeed(int Speed);
int SetPort(int Port);
void init_serial(void);
void comm_off(void);
public:
serial(int Port, int Speed, int Parity, int Bits, int StopBit);
serial &operator<<( char ch );
serial &operator<<( char *str );
serial &operator>>( char &ch );
~serial();
};


2 serial.cpp


/*------------------------------------------------------------------*
SERIAL.CPP

The following code shows how to take advantage of some of
the Turbo C++ extensions to the C++ language to do asynchronous
communications without having to write supporting assembly-
language routines.

This program bypasses the less-than-adequate PC BIOS
communications routines and installs a serial interrupt
handler. Direct access to PC hardware allows the program to
run at faster baud rates and eliminates the need for
the main program to continuously poll the serial port for
data; thus implementing background communications. Data that
enters the serial port is stored in a circular buffer.

* Compile this program with Test Stack Overflow OFF.

*------------------------------------------------------------------*/

#include <dos.h>
#include <conio.h>
#include <stdio.h>
#include <string.h>
#include "serial.h"

#define VERSION 0x0101

#define FALSE 0
#define TRUE (!FALSE)

#define NOERROR 0 /* No error */
#define BUFOVFL 1 /* Buffer overflowed */

#define ESC 0x1B /* ASCII Escape character */
#define ASCII 0x007F /* Mask ASCII characters */
#define SBUFSIZ 0x4000 /* Serial buffer size */

int SError = NOERROR;
int portbase = 0;
void interrupt(*oldvects[2])(...);

static char ccbuf[SBUFSIZ];
unsigned int startbuf = 0;
unsigned int endbuf = 0;


/* Handle communications interrupts and put them in ccbuf */
void interrupt com_int(...)
{
disable();
if ((inportb(portbase + IIR) & RX_MASK) == RX_ID)
{
if (((endbuf + 1) & SBUFSIZ - 1) == startbuf)
SError = BUFOVFL;

ccbuf[endbuf++] = inportb(portbase + RXR);
endbuf &= SBUFSIZ - 1;
}

/* Signal end of hardware interrupt */
outportb(ICR, EOI);
enable();
}

/* Output a character to the serial port */
serial& serial::operator<<( char x )
{
long int timeout = 0x0000FFFFL;

outportb(portbase + MCR, MC_INT | DTR | RTS);

// Wait for Clear To Send from modem
while ((inportb(portbase + MSR) & CTS) == 0)
if (!(--timeout))
return *this;

timeout = 0x0000FFFFL;

// Wait for transmitter to clear
while ((inportb(portbase + LSR) & XMTRDY) == 0)
if (!(--timeout))
return *this;

disable();
outportb(portbase + TXR, x);
enable();

return *this;
}

/* Output a string to the serial port */
serial& serial::operator<<( char *string )
{
while (*string)
{
(*this) << *string;
string++;
}
return *this;
}

/* This routine returns the current value in the buffer */
serial &serial::operator>>( char &ch )
{
if (endbuf == startbuf)
{
ch = -1;
return *this;
}

ch = ccbuf[startbuf];
startbuf++;
startbuf %= SBUFSIZ;
return *this;
}

/* Install our functions to handle communications */
void setvects(void)
{
oldvects[0] = getvect(0x0B);
oldvects[1] = getvect(0x0C);
setvect(0x0B, com_int);
setvect(0x0C, com_int);
}

/* Uninstall our vectors before exiting the program */
void resvects(void)
{
setvect(0x0B, oldvects[0]);
setvect(0x0C, oldvects[1]);
}

/* Turn on communications interrupts */
void i_enable(int pnum)
{
int c;

disable();
c = inportb(portbase + MCR) | MC_INT;
outportb(portbase + MCR, c);
outportb(portbase + IER, RX_INT);
//c = inportb(IMR) & (pnum == COM1 ? IRQ4 : IRQ3);
c = inportb(IMR) & (IRQ10);
outportb(IMR, c);
enable();
}

/* Turn off communications interrupts */
void i_disable(void)
{
int c;

disable();
//c = inportb(IMR) | ~IRQ3 | ~IRQ4;
c = inportb(IMR) | ~IRQ3 | ~IRQ4 | ~IRQ10;
outportb(IMR, c);
outportb(portbase + IER, 0);
c = inportb(portbase + MCR) & ~MC_INT;
outportb(portbase + MCR, c);
enable();
}

/* Tell modem that we're ready to go */
void comm_on(void)
{
int c, pnum;

pnum = (portbase == COM1BASE ? COM1 : COM2);
i_enable(pnum);
c = inportb(portbase + MCR) | DTR | RTS;
outportb(portbase + MCR, c);
}

/* Go off-line */
void serial::comm_off(void)
{
i_disable();
outportb(portbase + MCR, 0);
}

void serial::init_serial(void)
{
endbuf = startbuf = 0;
setvects();
comm_on();
}

serial::~serial()
{
comm_off();
resvects();
}

/* Set the port number to use */
int serial::SetPort(int Port)
{
int Offset, far *RS232_Addr;

switch (Port)
{ /* Sort out the base address */
case COM1 : portbase = 0x3e8;//0x3f8;
break;
case COM2 : portbase = 0x3e8;//0x2f8;
break;
default : return (-1);
}

return (0);
}

/* This routine sets the speed; will accept funny baud rates. */
/* Setting the speed requires that the DLAB be set on. */
int serial::SetSpeed(int Speed)
{
char c;
int divisor;

if (Speed == 0) /* Avoid divide by zero */
return (-1);
else
divisor = (int) (115200L/Speed);

if (portbase == 0)
return (-1);

disable();
c = inportb(portbase + LCR);
outportb(portbase + LCR, (c | 0x80)); /* Set DLAB */
outportb(portbase + DLL, (divisor & 0x00FF));
outportb(portbase + DLH, ((divisor >> 8) & 0x00FF));
outportb(portbase + LCR, c); /* Reset DLAB */
enable();

return (0);
}

/* Set other communications parameters */
int serial::SetOthers(int Parity, int Bits, int StopBit)
{
int setting;

if (portbase == 0) return (-1);
if (Bits < 5 || Bits > 8) return (-1);
if (StopBit != 1 && StopBit != 2) return (-1);
if (Parity != NO_PARITY && Parity != ODD_PARITY && Parity != EVEN_PARITY)
return (-1);

setting = Bits-5;
setting |= ((StopBit == 1) ? 0x00 : 0x04);
setting |= Parity;

disable();
outportb(portbase + LCR, setting);
enable();

return (0);
}

/* Set up the port */
serial::serial(int Port, int Speed, int Parity, int Bits, int StopBit)
{
flag = 0;
if (SetPort(Port))
flag = -1;
if (SetSpeed(Speed))
flag = -1;
if (SetOthers(Parity, Bits, StopBit))
flag = -1;

if (!flag)
init_serial();
}

/* Control-Break interrupt handler */
int c_break(void)
{
i_disable();
fprintf(stderr, "\nStill online.\n");

return(0);
}

main()
{
/* Communications parameters */
int port = COM1;
int speed = 2400;
int parity = NO_PARITY;
int bits = 8;
int stopbits = 1;

int done = FALSE;
char c;

serial comport(port, speed, parity, bits, stopbits);

ctrlbrk(c_break);

fprintf(stdout, "TURBO C TERMINAL\n"
"...You're now in terminal mode, "
"press [ESC] to quit...\n\n");

/*
The main loop acts as a dumb terminal. We repeatedly
check the keyboard buffer, and communications buffer.
*/
do {
if (kbhit())
{
/* Look for an Escape key */
switch (c=getch())
{
case ESC: done = TRUE; /* Exit program */
break;

/* You may want to handle other keys here... */
}
if (!done)
comport << c;
}
comport >> c;
if (c != -1)
fputc(c & ASCII, stdout);

} while (!done && !SError);

/* Check for errors */
switch (SError)
{
case NOERROR: fprintf(stderr, "\nbye.\n");
return (0);

case BUFOVFL: fprintf(stderr, "\nBuffer Overflow.\n");
return (99);

default: fprintf(stderr, "\nUnknown Error, SError = %d\n",
SError);
return (99);
}
}


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满桌烟灰 2000-09-06
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1。一般COM1/COM3共用IRQ4,COM2/COM4共用IRQ3。
2。一般COM1=0X3F8,COM2=0X2F8,COM3=0X3E8,COM4=0X2E8。
3。portbase初值不能为零,应为0x3f8/0x2f8/0x3e8/0x2e8。
满桌烟灰 2000-09-06
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1~{!#~}COM1~{:M~}COM3~{92SC~}IRQ4~{#,~}COM2~{:M~}COM4~{92SC~}IRQ3~{!#~}
2~{!#~}COM~{;y5XV74mNs#,R;0c~}COM1=0X3F8~{#,~}COM2=0X2F8~{#,~}COM3=0X3E8~{#,~}COM4=0X2E8~{!#~}
3~{!#~}portbase~{1dA?3uV5IhVC4mNs#,2;D\N*Ac#,S&N*~}0x3f8/0x2f8/0x3e8/0x2e8~{VP5DR;8v!#~}

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