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modified while adding pic18 support

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This commit is contained in:
skarg
2005-04-20 17:09:26 +00:00
parent d6033b03a3
commit 4646df1188
13 changed files with 1183 additions and 204 deletions
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bacnet-stack/ports/pic18/rs485.c
+372 -91
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@@ -1,37 +1,27 @@
/*####COPYRIGHTBEGIN####
-------------------------------------------
Copyright (C) 2004 Steve Karg
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
The Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307
USA.
As a special exception, if other files instantiate templates or
use macros or inline functions from this file, or you compile
this file and link it with other works to produce a work based
on this file, this file does not by itself cause the resulting
work to be covered by the GNU General Public License. However
the source code for this file must still be made available in
accordance with section (3) of the GNU General Public License.
This exception does not invalidate any other reasons why a work
based on this file might be covered by the GNU General Public
License.
-------------------------------------------
####COPYRIGHTEND####*/
/**************************************************************************
*
* Copyright (C) 2005 Steve Karg <skarg@users.sourceforge.net>
*
* 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 THE AUTHORS OR COPYRIGHT HOLDERS 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.
*
*********************************************************************/
// The module handles sending data out the RS-485 port
// and handles receiving data from the RS-485 port.
@@ -39,76 +29,367 @@
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include "hardware.h"
#include "mstp.h"
// Transmits a Frame on the wire
// public port info
extern volatile struct mstp_port_struct_t MSTP_Port;
static uint32_t RS485_Baud_Rate = 9600;
// UART transmission buffer and index
static volatile uint8_t RS485_Tx_Buffer[MAX_MPDU];
static volatile uint8_t RS485_Tx_Index = 0;
static volatile uint8_t RS485_Tx_Length = 0;
static volatile char RS485_Tx_Postdrive_Delay = 0;
static struct
{
unsigned TransmitStart:1; // TRUE if we are requested to transmit
unsigned TransmitComplete:1; // TRUE if we are finished transmitting frame
} RS485_Flags;
// Duplicate of the RCSTA reg used due to the double buffering of the
// fifo. Reading the RCREG reg will cause the second RCSTA reg to be
// loaded if there is one. */
struct _rcstabits
{
unsigned char RX9D:1;
unsigned char OERR:1;
unsigned char FERR:1;
unsigned char ADDEN:1;
unsigned char CREN:1;
unsigned char SREN:1;
unsigned char RX9:1;
unsigned char SPEN:1;
};
volatile static enum
{
RS485_STATE_IDLE = 0,
RS485_STATE_RX_DATA = 1,
RS485_STATE_RX_CHECKSUM = 2,
RS485_STATE_RX_PROCESS = 3,
RS485_STATE_TX_DATA = 4,
RS485_STATE_WAIT_FOR_ACK = 5,
RS485_STATE_WAIT_COMPLETE = 6,
RS485_STATE_TX_GLOBAL_ACK = 7,
RS485_STATE_TX_POSTDRIVE_DELAY = 8,
RS485_STATE_ERROR = 9,
RS485_STATE_RX_TEST = 10,
RS485_STATE_RX_TEST_EEPROM = 11,
RS485_STATE_RX_TEST_DELAY = 12,
RS485_STATE_TX_TEST_WAIT = 13,
RS485_STATE_TX_TEST = 14
} RS485_State;
/****************************************************************************
* DESCRIPTION: Transmits a frame using the UART
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Send_Frame(
struct mstp_port_struct_t *mstp_port, // port specific data
volatile struct mstp_port_struct_t *mstp_port, // port specific data
uint8_t *buffer, // frame to send (up to 501 bytes of data)
uint16_t nbytes) // number of bytes of data (up to 501)
{
uint8_t HeaderCRC; // used for running CRC calculation
// do we check for tx buffer in-use?
// Or do we just stop the in-progress transmission?
// Drop any transmission in progress, but don't worry about
// cleaning up the hardware - the start routine will handle that
(void)buffer; // FIXME: temp until we implement this code
(void)nbytes; // FIXME: temp until we implement this code
// in order to avoid line contention
//while (mstp_port->SilenceTimer < Tturnaround)
//{
// wait, yield, or whatever
//}
// Disable the receiver, and enable the transmit line driver.
// Transmit the preamble octets X'55', X'FF'.
// As each octet is transmitted, set SilenceTimer to zero.
HeaderCRC = 0xFF;
// Transmit the Frame Type, Destination Address, Source Address,
// and Data Length octets. Accumulate each octet into HeaderCRC.
// As each octet is transmitted, set SilenceTimer to zero.
// Transmit the ones-complement of HeaderCRC. Set SilenceTimer to zero.
// If there are data octets, initialize DataCRC to X'FFFF'.
// Transmit any data octets. Accumulate each octet into DataCRC.
// As each octet is transmitted, set SilenceTimer to zero.
// Transmit the ones-complement of DataCRC, least significant octet first.
// As each octet is transmitted, set SilenceTimer to zero.
// Wait until the final stop bit of the most significant CRC octet
// has been transmitted but not more than Tpostdrive.
// Disable the transmit line driver.
// Disable the interrupt since it depends on the global transmit buffer.
USART_TX_INT_DISABLE();
switch (RS485_State)
{
case RS485_STATE_TX_DATA:
case RS485_STATE_WAIT_FOR_ACK:
case RS485_STATE_WAIT_COMPLETE:
case RS485_STATE_TX_GLOBAL_ACK:
RS485_State = RS485_STATE_IDLE;
break;
}
// load the frame
RS485_Tx_Length = 0;
while (buffer && nbytes)
{
RS485_Tx_Buffer[RS485_Tx_Length] = *buffer;
buffer++;
nbytes--;
RS485_Tx_Length++;
// check bounds - should this error be indicated somehow?
// perhaps not send the message?
if (RS485_Tx_Length >= MAX_MPDU)
break;
}
// signal the task to start sending when it is ready
RS485_Flags.TransmitStart = TRUE;
return;
}
// called by timer, interrupt(?) or other thread
void RS485_Check_UART_Data(struct mstp_port_struct_t *mstp_port)
/****************************************************************************
* DESCRIPTION: Processes the next RS485 byte for transmit
* RETURN: none
* ALGORITHM: none
* NOTES: Called by interrupt service routine (ISR)
*****************************************************************************/
void RS485_Transmit_Interrupt(void)
{
if (mstp_port->ReceiveError == true)
uint8_t data; // data byte to send
switch (RS485_State)
{
// wait for state machine to clear this
}
// wait for state machine to read from the DataRegister
else if (mstp_port->DataAvailable == false)
{
// check for data
// if error,
// ReceiveError = TRUE;
// return;
mstp_port->DataRegister = 0; // FIXME: Get this data from UART or buffer
// if data is ready,
// DataAvailable = TRUE;
// return;
case RS485_STATE_TX_DATA:
RS485_Tx_Index++;
if (RS485_Tx_Index < RS485_Tx_Length)
{
data = RS485_Tx_Buffer[RS485_Tx_Index];
USART_TRANSMIT(data);
MSTP_Port.SilenceTimer = 0;
}
else
{
// wait until the last bit is sent
while (!USART_TX_EMPTY());
RS485_TRANSMIT_DISABLE();
// wait 2 characters after sending (min=15 bit times)
RS485_Tx_Postdrive_Delay = 2;
RS485_State = RS485_STATE_TX_POSTDRIVE_DELAY;
USART_TRANSMIT(0);
}
break;
case RS485_STATE_TX_POSTDRIVE_DELAY:
// after the message is sent, we wait a certain
// number of character times to get a delay
if (RS485_Tx_Postdrive_Delay)
{
RS485_Tx_Postdrive_Delay--;
if (RS485_Tx_Postdrive_Delay == 0)
RS485_State = RS485_STATE_WAIT_COMPLETE;
USART_TRANSMIT(0);
}
else
RS485_State = RS485_STATE_WAIT_COMPLETE;
break;
case RS485_STATE_WAIT_COMPLETE:
// wait until the last delay bit is shifted
while (!USART_TX_EMPTY());
USART_TX_INT_DISABLE();
RS485_Flags.TransmitComplete = TRUE;
RS485_State = RS485_STATE_IDLE;
USART_RX_SETUP();
break;
default:
break;
}
return;
}
/****************************************************************************
* DESCRIPTION: Processes the RS485 message to be sent
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Process_Tx_Message(void)
{
if (RS485_Flags.TransmitComplete)
RS485_Flags.TransmitComplete = FALSE;
// start a new transmisstion if we are ready
if (RS485_Flags.TransmitStart && (RS485_State == RS485_STATE_IDLE))
{
// Disable the receiver
USART_RX_INT_DISABLE();
USART_CONTINUOUS_RX_DISABLE();
// Enable the transmit line driver and interrupts
RS485_TRANSMIT_ENABLE();
RS485_State = RS485_STATE_TX_DATA;
// Configure the ISR handler for an outgoing message
RS485_Tx_Index = 0;
// update the flags for beginning a send
RS485_Flags.TransmitComplete = FALSE;
RS485_Flags.TransmitStart = FALSE;
// send the first byte
USART_TRANSMIT(RS485_Tx_Buffer[0]);
USART_TX_SETUP();
}
return;
}
/****************************************************************************
* DESCRIPTION: Checks for data on the receive UART, and handles errors
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Check_UART_Data(volatile struct mstp_port_struct_t *mstp_port)
{
struct _rcstabits rcstabits; // reading it more than once gets wrong data
// check for data
if (USART_RX_COMPLETE())
{
// Read the data and the Rx status reg
rcstabits = USART_RX_STATUS();
mstp_port->DataRegister = USART_RECEIVE();
// Check for buffer overrun error
if (rcstabits.OERR)
{
// clear the error
USART_CONTINUOUS_RX_DISABLE();
USART_CONTINUOUS_RX_ENABLE();
// let the state machine know
mstp_port->ReceiveError = TRUE;
}
// Check for framing errors
else if (USART_RX_FRAME_ERROR())
{
// let the state machine know
mstp_port->FramingError = TRUE;
mstp_port->ReceiveError = TRUE;
}
// We read a good byte
else
{
// state machine will clear this
mstp_port->DataAvailable = TRUE;
}
}
return;
}
/****************************************************************************
* DESCRIPTION: Receives a data byte from the USART
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Receive_Interrupt(void)
{
// get as many bytes as we can get
for (;;)
{
RS485_Check_UART_Data(&MSTP_Port);
if (MSTP_Port.ReceiveError || MSTP_Port.DataAvailable)
MSTP_Receive_Frame_FSM(&MSTP_Port);
else
break;
}
return;
}
/****************************************************************************
* DESCRIPTION: Returns the baud rate that we are currently running at
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
uint32_t RS485_Get_Baud_Rate(void)
{
return RS485_Baud_Rate;
}
/****************************************************************************
* DESCRIPTION: Sets the baud rate for the chip USART
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Set_Baud_Rate(uint32_t baud)
{
if (baud < 19200)
RS485_Baud_Rate = 9600;
else if (baud < 38400)
RS485_Baud_Rate = 19200;
else if (baud < 57600)
RS485_Baud_Rate = 38400;
else if (baud < 57600)
RS485_Baud_Rate = 57600;
else if (baud < 115200)
RS485_Baud_Rate = 76800;
else
RS485_Baud_Rate = 115200;
}
void RS485_Initialize_Baud(void)
{
// setup USART Baud Rate Generator
// see BAUD RATES FOR ASYNCHRONOUS MODE in Data Book
/* Fosc=20MHz
BRGH=1 BRGH=0
Rate SPBRG Rate SPBRG
------- ----- ------- -----
9615 129 9469 32
19230 64 19530 15
37878 32 78130 3
56818 21 104200 2
113630 10 312500 0
250000 4
625000 1
1250000 0
*/
switch (RS485_Baud_Rate)
{
case 19200:
SPBRG = 64;
TXSTAbits.BRGH=1;
break;
case 38400:
SPBRG = 32;
TXSTAbits.BRGH=1;
break;
case 57600:
SPBRG = 21;
TXSTAbits.BRGH=1;
break;
case 76800:
SPBRG = 3;
TXSTAbits.BRGH=0;
break;
case 115200:
SPBRG = 10;
TXSTAbits.BRGH=1;
break;
case 9600:
default:
SPBRG = 129;
TXSTAbits.BRGH=1;
break;
}
/* select async mode */
TXSTAbits.SYNC=0;
/* serial port enable */
RCSTAbits.SPEN=1;
}
/****************************************************************************
* DESCRIPTION: Initializes the RS485 hardware and variables, and starts in
* receive mode.
* RETURN: none
* ALGORITHM: none
* NOTES: none
*****************************************************************************/
void RS485_Initialize(void)
{
RS485_Initialize_Baud();
/* configure interrupts */
USART_TX_INT_DISABLE();
USART_RX_INT_ENABLE();
// configure USART for receiving
// since the TX will handle setting up for transmit
USART_CONTINUOUS_RX_ENABLE();
/* since we are using RS485,
we need to explicitly say
transmit enable or not */
RS485_TRANSMIT_DISABLE();
}