?? serdpcpl.c
字號:
/****************************************************************************
*****************************************************************************
serdpcpl.c - Serial Routines - DOS PC Compatible
written for: Ascension Technology Corporation
PO Box 527
Burlington, Vermont 05402
802-655-7879
written by: Jeff Finkelstein
Modification History:
10/18/90 jf - released
11/12/90 jf - add getdosticks() to allow Polled mode operation
at 19200 even on a pretty slow machine
4/16/91 jf - renamed file to serdpcpl.c
6/18/91 jf - added FOB baudrates
12/5/93 jf - fixed bug in getserialrecord to assure that a
character with an error does not get into the
rxbuffer
12/23/92 jf - added baudratebit definitions to allow
for compatibility with UNIX
1/31/93 jf - send_serial_cmd modified to be able to send out
rs232 to fbb commands to addr 30
10/21/93 jf - remove getdosticks() and replaced with GETTICKS
<<<< Copyright 1990 Ascension Technology Corporation >>>>
*****************************************************************************
****************************************************************************/
#include <stdio.h> /* general I/O */
#include <time.h> /* clock functions */
#include <dos.h> /* int86 call */
#include "asctech.h"
#include "compiler.h"
#include "menu.h"
#include "pctimer.h"
#include "serial.h"
/*
Prototype for DOS Systems Only
*/
void interrupt far serialisr(void);
/*
Global Variables
*/
short com_base = COM1BASE; /* holds the base address of the 8250 */
short comport = COM1; /* holds the comport # */
char * sys_com_port[2] ={"com1","com2"};
/*
The FOB Bird uses a different set of Baud Rates as compared
to the standard Bird
*/
long baud = 9600L; /* holds the default baud rate */
long baudratetable[] = {115200L,
57600L,
38400L,
19200L,
9600L,
4800L, /* holds the baud rate selections */
2400L}; /* for the FOB Bird */
/*
Used for compatibility with UNIX versions
*/
short baudspeedbits = 7; /* holds the current bit definition */
short baudspeedbittable[] = {11,
10,
9,
8,
7,
6,
5}; /* holds the bitspeed definition */
short serialconfigsaved = FALSE; /* flag indicates serial port saved */
/*
UART variable Storage
*/
unsigned char olddivisorlow; /* holds the old divisor low value */
unsigned char olddivisorhigh; /* holds the old divisor high value */
unsigned char oldlinecont; /* holds the old line control value */
unsigned char oldinterenable; /* holds the old interrupt enable value */
unsigned char oldmodemcont; /* holds the old modem control value */
short phaseerror_count = 0; /* holds the phase errors */
short rxerrors = 0; /* holds the rx line errors */
/*
Define RS232 to FBB Global Address
*/
short rs232tofbbaddr = 0;
/*
configserialport - Configure the Serial Port connected to the BIRD
Prototype in: serial.h
Parameters Passed: void
Return Value: TRUE if successfull, else FALSE
Remarks:
Unfortunately, the PC ROM BIOS does NOT support baud
rates upto 19200. Therefore, this routine must talk
directly to the hardware to configure the serial port
...this is not a problem in a PC environment since the
I/O map is fixed for COM1 and COM2.
*** NOTE ***
The 8250 UART cannot withstand back to back writes (OUTs). The
compiler does not generate contiguous 'out dx,al' instructions
and therefore there are delays between the OUTPUTs. If written in
assembly language, the typical BIOS type delay is a 'jmp' to the next
instruction. For example...
out dx,al ; output to serial port
jmp $+2 ; jump to the PC + 2
out dx,al ; output to serial port
or
out dx,al ; output to serial port
clc ; clear carry
jnc $+2 ; jump to the PC + 2
out dx,al ; output to serial port
*/
int configserialport(void)
{
unsigned divisor;
/*
Verify the comport and set the Base Address
*/
switch (comport)
{
case COM1:
com_base = COM1BASE; /* set the new I/O addr */
break;
case COM2:
com_base = COM2BASE; /* set the new I/O addr */
break;
default:
printf("\n** ERROR ** invalid COM port\n");
return(FALSE);
}
/*
disable the interrupts
*/
OUTPORTB(com_base + INTERENABLE, 0);
/*
assume that there are NO CHARACTERS CURRENTLY in the Tx Buffer
and change the baud rate
*/
OUTPORTB(com_base + LINECONT, DLAB);
/*
Set the least significant byte and then the most significant
byte of the baud rate divisor
*/
divisor = 115200L/baud;
OUTPORTB(com_base, (divisor & 0xff));
OUTPORTB(com_base + 1, ((divisor & 0xff00) >> 8));
/*
Set the Stop Bits = 1, Word Length = 8 and Parity = None
*/
OUTPORTB(com_base + LINECONT, STOP_WORDLEN_PARITY);
/*
Clear the Rx Buffer
*/
clear_rx();
/*
Assert DTR...just in case the cable uses the DTR signal
*/
OUTPORTB(com_base + MODEMCONT,1);
return(TRUE);
}
/*
saveserialconfig - save serial port configuration
Prototype in: serial.h
Parameters Passed: void
Return Value: void
Remarks: saves the current configuration of the serial port
*/
int saveserialconfig()
{
/*
Save the Current Com Port Configuration Regs including:
Divisor, Interrupt Enable, Line Control, Modem Control
*/
oldlinecont = INPORTB(com_base + LINECONT); /* save the old line control value */
OUTPORTB(com_base + LINECONT, DLAB); /* set DLAB to get the divisor */
olddivisorlow = INPORTB(com_base); /* save the divisor low */
olddivisorhigh = INPORTB(com_base + 1); /* save the divisor high */
OUTPORTB(com_base + LINECONT,oldlinecont & 0x7f); /* reset DLAB to get the divisor */
oldinterenable = INPORTB(com_base + INTERENABLE); /* save the interrupt enable reg */
oldmodemcont = INPORTB(com_base + MODEMCONT); /* save the interrupt enable reg */
return(TRUE);
}
/*
restoreserialconfig - Restore the original serial port configuration
Prototype in: serial.h
Parameters Passed: void
Return Value: void
Remarks: restores the configuration of the serial port
*/
void restoreserialconfig()
{
/*
Do not Restore if not previously stored
*/
if (!serialconfigsaved)
return;
/*
Restore the Com Port Configuration Regs including:
Divisor, Interrupt Enable, Line Control, Modem Control
*/
OUTPORTB(com_base + LINECONT, DLAB); /* set DLAB to get the divisor */
OUTPORTB(com_base,olddivisorlow); /* restore the divisor low */
OUTPORTB(com_base + 1,olddivisorhigh); /* restore the divisor high */
OUTPORTB(com_base + LINECONT,oldlinecont); /* reset DLAB to get the divisor */
OUTPORTB(com_base + INTERENABLE,oldinterenable); /* restore the interrupt enable reg */
OUTPORTB(com_base + MODEMCONT,oldmodemcont); /* restore the interrupt enable reg */
}
/*
clearrx - Read the characters out of the Rx buffer if available
Prototype in: serial.h
Parameters Passed: void
Return Value: void
Remarks: clears the rx buffer and rx errors if any
*/
void clear_rx()
{
phaseerror_count = 0; /* clear the phase counter */
while (get_serial_char() != NODATAAVAIL); /* get chars */
INPORTB(com_base + LINESTATUS); /* clear errors */
}
/*
get_serial_record - Get a record from the serial port
Prototype in: serial.h
Parameters Passed: rxbuf - pointer to a buffer to store the
received characters
recsize - number of characters to receive
outputmode - POINT, CONTINUOUS or STREAM
Return Value: If successful, returns recsize
else, RXERRORS if Rx errors were detected while
receiving data, or RXPHASEERRORS if in POINT or
CONTINUOUS mode and a phase error is detected.
Remarks: A record of data has the MSB of the first
character set to a 1. The routine verifies that
the first character received is in PHASE. If
in STREAM mode, the routine resynches and tries
to capture the data into the rxbuf. If in POINT
or CONTINUOUS mode, then the routine returns
indicating a RXPHASEERROR.
*/
int get_serial_record(rxbuf, recsize, outputmode)
unsigned char * rxbuf;
short recsize;
short outputmode;
{
short rxcount;
short rxchar;
short resynch;
char * rxbufptr;
resynch = TRUE;
do
{
if (resynch)
{
rxcount = 0; /* initialize char counter */
rxbufptr = rxbuf; /* setup buffer pointer */
resynch = FALSE;
}
/*
Get first character and if error and NOT in STREAM mode..return
*/
if (rxcount == 0)
{
if ((rxchar = waitforchar()) < 0)
{
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