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//---------------------------------------------------------------------------
// Copyright (C) 1999 Dallas Semiconductor Corporation, All Rights Reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
// Except as contained in this notice, the name of Dallas Semiconductor
// shall not be used except as stated in the Dallas Semiconductor
// Branding Policy.
//---------------------------------------------------------------------------
//
// ds2480ut.c - DS2480 utility functions.
//
// Version: 1.03
//
// History: 1.00 -> 1.01 Default PDSRC changed from 0.83 to 1.37V/us
// in DS2480Detect. Changed to use msDelay instead
// of Delay.
//
// 1.01 -> 1.02 Changed global declarations from 'uchar' to 'int'.
// Changed DSO/WORT from 7 to 10us in DS2480Detect.
//
// 1.02 -> 1.03 Removed caps in #includes for Linux capatibility
#include "ds2480.h"
#include "mlan.h"
// external COM functions required
extern void FlushCOM(void);
extern int WriteCOM(int, uchar *);
extern int ReadCOM(int, uchar *);
extern void BreakCOM(void);
//extern void SetBaudCOM(uchar);
extern void msDelay(int);
// exportable functions
int DS2480Detect(void);
int DS2480ChangeBaud(uchar);
// global DS2480 state
int UMode = MODSEL_COMMAND; // current DS2480 command or data mode stateuchar
int UBaud = PARMSET_9600; // current DS2480 baud rate
int USpeed = SPEEDSEL_FLEX; // current DS2480 MicroLAN communication speed
int ULevel = MODE_NORMAL; // current DS2480 MicroLAN level
//---------------------------------------------------------------------------
// Attempt to resyc and detect a DS2480
//
// Returns: TRUE - DS2480 detected successfully
// FALSE - Could not detect DS2480
//
int DS2480Detect(void)
{
uchar sendpacket[10],readbuffer[10];
short sendlen=0;
// reset modes
UMode = MODSEL_COMMAND;
UBaud = PARMSET_9600;
USpeed = SPEEDSEL_FLEX;
// set the baud rate to 9600
SetBaudCOM((uchar)UBaud);
// send a break to reset the DS2480
BreakCOM();
// delay to let line settle
msDelay(2);
// flush the buffers
FlushCOM();
// send the timing byte
sendpacket[0] = 0xC1;
if (WriteCOM(1,sendpacket) != 1)
return FALSE;
// set the FLEX configuration parameters
// default PDSRC = 1.37Vus
sendpacket[sendlen++] = CMD_CONFIG | PARMSEL_SLEW | PARMSET_Slew1p37Vus;
// default W1LT = 12us
sendpacket[sendlen++] = CMD_CONFIG | PARMSEL_WRITE1LOW | PARMSET_Write12us;
// default DSO/WORT = 10us
sendpacket[sendlen++] = CMD_CONFIG | PARMSEL_SAMPLEOFFSET | PARMSET_SampOff10us;
// construct the command to read the baud rate (to test command block)
sendpacket[sendlen++] = CMD_CONFIG | PARMSEL_PARMREAD | (PARMSEL_BAUDRATE >> 3);
// also do 1 bit operation (to test 1-Wire block)
sendpacket[sendlen++] = CMD_COMM | FUNCTSEL_BIT | UBaud | BITPOL_ONE;
// flush the buffers
FlushCOM();
// send the packet
if (WriteCOM(sendlen,sendpacket))
{
// read back the response
if (ReadCOM(5,readbuffer) == 5)
{
// look at the baud rate and bit operation
// to see if the response makes sense
if (((readbuffer[3] & 0xF1) == 0x00) &&
((readbuffer[3] & 0x0E) == UBaud) &&
((readbuffer[4] & 0xF0) == 0x90) &&
((readbuffer[4] & 0x0C) == UBaud))
return TRUE;
}
}
return FALSE;
}
//---------------------------------------------------------------------------
// Change the DS2480 from the current baud rate to the new baud rate.
//
// 'newbaud' - the new baud rate to change to, defined as:
// PARMSET_9600 0x00
// PARMSET_19200 0x02
// PARMSET_57600 0x04
// PARMSET_115200 0x06
//
// Returns: current DS2480 baud rate.
//
int DS2480ChangeBaud(uchar newbaud)
{
int rt=FALSE;
uchar readbuffer[5],sendpacket[5],sendpacket2[5];
int sendlen=0,sendlen2=0;
// see if diffenent then current baud rate
if (UBaud == newbaud)
return TRUE;
else
{
// build the command packet
// check if correct mode
if (UMode != MODSEL_COMMAND)
{
UMode = MODSEL_COMMAND;
sendpacket[sendlen++] = MODE_COMMAND;
}
// build the command
sendpacket[sendlen++] = CMD_CONFIG | PARMSEL_BAUDRATE | newbaud;
// flush the buffers
FlushCOM();
// send the packet
if (!WriteCOM(sendlen,sendpacket))
rt = FALSE;
else
{
// make sure buffer is flushed
msDelay(5);
// change our baud rate
SetBaudCOM(newbaud);
UBaud = newbaud;
// wait for things to settle
msDelay(5);
// build a command packet to read back baud rate
sendpacket2[sendlen2++] = CMD_CONFIG | PARMSEL_PARMREAD | (PARMSEL_BAUDRATE >> 3);
// flush the buffers
FlushCOM();
// send the packet
if (WriteCOM(sendlen2,sendpacket2))
{
// read back the 1 byte response
if (ReadCOM(1,readbuffer) == 1)
{
// verify correct baud
if (((readbuffer[0] & 0x0E) == (sendpacket[sendlen-1] & 0x0E)))
rt = TRUE;
}
}
}
}
// if lost communication with DS2480 then reset
if (rt != TRUE)
DS2480Detect();
return UBaud;
}
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