2107 lines
70 KiB
C
2107 lines
70 KiB
C
//*****************************************************************************
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//
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// can.c - Driver for the CAN module.
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//
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// Copyright (c) 2006-2013 Texas Instruments Incorporated. All rights reserved.
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// Software License Agreement
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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//
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// Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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//
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// Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the
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// distribution.
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//
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// Neither the name of Texas Instruments Incorporated nor the names of
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// its contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// This is part of revision 1.1 of the Tiva Peripheral Driver Library.
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//
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//*****************************************************************************
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//*****************************************************************************
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//
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//! \addtogroup can_api
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//! @{
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//
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//*****************************************************************************
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#include <stdbool.h>
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#include <stdint.h>
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#include "inc/hw_can.h"
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#include "inc/hw_ints.h"
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#include "inc/hw_nvic.h"
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#include "inc/hw_memmap.h"
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#include "inc/hw_sysctl.h"
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#include "inc/hw_types.h"
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#include "driverlib/can.h"
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#include "driverlib/debug.h"
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#include "driverlib/interrupt.h"
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//*****************************************************************************
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//
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// This is the maximum number that can be stored as an 11bit Message
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// identifier.
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//
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//*****************************************************************************
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#define CAN_MAX_11BIT_MSG_ID 0x7ff
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//*****************************************************************************
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//
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// The maximum CAN bit timing divisor is 19.
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//
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//*****************************************************************************
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#define CAN_MAX_BIT_DIVISOR 19
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//*****************************************************************************
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//
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// The minimum CAN bit timing divisor is 4.
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//
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//*****************************************************************************
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#define CAN_MIN_BIT_DIVISOR 4
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//*****************************************************************************
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//
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// The maximum CAN pre-divisor is 1024.
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//
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//*****************************************************************************
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#define CAN_MAX_PRE_DIVISOR 1024
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//*****************************************************************************
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//
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// The minimum CAN pre-divisor is 1.
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//
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//*****************************************************************************
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#define CAN_MIN_PRE_DIVISOR 1
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//*****************************************************************************
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//
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// Converts a set of CAN bit timing values into the value that needs to be
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// programmed into the CAN_BIT register to achieve those timings.
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//
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//*****************************************************************************
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#define CAN_BIT_VALUE(seg1, seg2, sjw) \
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((((seg1 - 1) << CAN_BIT_TSEG1_S) & \
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CAN_BIT_TSEG1_M) | \
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(((seg2 - 1) << CAN_BIT_TSEG2_S) & \
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CAN_BIT_TSEG2_M) | \
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(((sjw - 1) << CAN_BIT_SJW_S) & \
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CAN_BIT_SJW_M))
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//*****************************************************************************
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//
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// This table is used by the CANBitRateSet() API as the register defaults for
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// the bit timing values.
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//
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//*****************************************************************************
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static const uint16_t g_ui16CANBitValues[] =
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{
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CAN_BIT_VALUE(2, 1, 1), // 4 clocks/bit
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CAN_BIT_VALUE(3, 1, 1), // 5 clocks/bit
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CAN_BIT_VALUE(3, 2, 2), // 6 clocks/bit
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CAN_BIT_VALUE(4, 2, 2), // 7 clocks/bit
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CAN_BIT_VALUE(4, 3, 3), // 8 clocks/bit
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CAN_BIT_VALUE(5, 3, 3), // 9 clocks/bit
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CAN_BIT_VALUE(5, 4, 4), // 10 clocks/bit
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CAN_BIT_VALUE(6, 4, 4), // 11 clocks/bit
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CAN_BIT_VALUE(6, 5, 4), // 12 clocks/bit
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CAN_BIT_VALUE(7, 5, 4), // 13 clocks/bit
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CAN_BIT_VALUE(7, 6, 4), // 14 clocks/bit
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CAN_BIT_VALUE(8, 6, 4), // 15 clocks/bit
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CAN_BIT_VALUE(8, 7, 4), // 16 clocks/bit
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CAN_BIT_VALUE(9, 7, 4), // 17 clocks/bit
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CAN_BIT_VALUE(9, 8, 4), // 18 clocks/bit
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CAN_BIT_VALUE(10, 8, 4) // 19 clocks/bit
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};
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//*****************************************************************************
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//
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//! \internal
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//! Checks a CAN base address.
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//!
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//! \param ui32Base is the base address of the CAN controller.
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//!
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//! This function determines if a CAN controller base address is valid.
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//!
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//! \return Returns \b true if the base address is valid and \b false
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//! otherwise.
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//
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//*****************************************************************************
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#ifdef DEBUG
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static bool
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_CANBaseValid(uint32_t ui32Base)
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{
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return((ui32Base == CAN0_BASE) || (ui32Base == CAN1_BASE));
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}
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#endif
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//*****************************************************************************
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//
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//! Returns the CAN controller interrupt number.
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//!
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//! \param ui32Base is the base address of the selected CAN controller
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//!
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//! This function returns the interrupt number for the CAN module with the base
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//! address passed in the \e ui32Base parameter.
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//!
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//! \return Returns a CAN interrupt number or 0 if the interrupt does not
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//! exist.
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//
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//*****************************************************************************
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static uint_fast8_t
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_CANIntNumberGet(uint32_t ui32Base)
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{
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uint_fast8_t ui8Int;
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ASSERT((ui32Base == CAN0_BASE) || (ui32Base == CAN1_BASE));
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ui8Int = 0;
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//
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// Find the valid interrupt number for this CAN controller.
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//
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if(CLASS_IS_BLIZZARD)
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{
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if(ui32Base == CAN0_BASE)
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{
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ui8Int = INT_CAN0_BLIZZARD;
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}
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else if(ui32Base == CAN1_BASE)
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{
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ui8Int = INT_CAN1_BLIZZARD;
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}
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}
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return(ui8Int);
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}
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//*****************************************************************************
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//
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//! \internal
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//! Copies data from a buffer to the CAN Data registers.
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//!
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//! \param pui8Data is a pointer to the data to be written out to the CAN
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//! controller's data registers.
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//! \param pui32Register is an uint32_t pointer to the first register of the
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//! CAN controller's data registers. For example, in order to use the IF1
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//! register set on CAN controller 0, the value would be: \b CAN0_BASE \b +
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//! \b CAN_O_IF1DA1.
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//! \param iSize is the number of bytes to copy into the CAN controller.
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//!
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//! This function takes the steps necessary to copy data from a contiguous
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//! buffer in memory into the non-contiguous data registers used by the CAN
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//! controller. This function is rarely used outside of the CANMessageSet()
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//! function.
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//!
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//! \return None.
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//
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//*****************************************************************************
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static void
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_CANDataRegWrite(uint8_t *pui8Data, uint32_t *pui32Register, uint32_t ui32Size)
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{
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uint32_t ui32Idx, ui32Value;
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//
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// Loop always copies 1 or 2 bytes per iteration.
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//
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for(ui32Idx = 0; ui32Idx < ui32Size; )
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{
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//
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// Write out the data 16 bits at a time since this is how the registers
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// are aligned in memory.
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//
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ui32Value = pui8Data[ui32Idx++];
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//
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// Only write the second byte if needed otherwise it will be zero.
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//
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if(ui32Idx < ui32Size)
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{
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ui32Value |= (pui8Data[ui32Idx++] << 8);
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}
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HWREG(pui32Register++) = ui32Value;
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}
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}
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//*****************************************************************************
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//
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//! \internal
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//! Copies data from a buffer to the CAN Data registers.
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//!
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//! \param pui8Data is a pointer to the location to store the data read from
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//! the CAN controller's data registers.
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//! \param pui32Register is an uint32_t pointer to the first register of the
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//! CAN controller's data registers. For example, in order to use the IF1
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//! register set on CAN controller 1, the value would be: \b CAN0_BASE \b +
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//! \b CAN_O_IF1DA1.
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//! \param iSize is the number of bytes to copy from the CAN controller.
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//!
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//! This function takes the steps necessary to copy data to a contiguous buffer
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//! in memory from the non-contiguous data registers used by the CAN
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//! controller. This function is rarely used outside of the CANMessageGet()
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//! function.
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//!
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//! \return None.
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//
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//*****************************************************************************
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static void
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_CANDataRegRead(uint8_t *pui8Data, uint32_t *pui32Register, uint32_t ui32Size)
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{
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uint32_t ui32Idx, ui32Value;
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//
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// Loop always copies 1 or 2 bytes per iteration.
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//
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for(ui32Idx = 0; ui32Idx < ui32Size; )
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{
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//
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// Read out the data 16 bits at a time since this is how the registers
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// are aligned in memory.
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//
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ui32Value = HWREG(pui32Register++);
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//
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// Store the first byte.
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//
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pui8Data[ui32Idx++] = (uint8_t)ui32Value;
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//
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// Only read the second byte if needed.
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//
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if(ui32Idx < ui32Size)
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{
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pui8Data[ui32Idx++] = (uint8_t)(ui32Value >> 8);
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}
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}
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}
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//*****************************************************************************
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//
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//! Initializes the CAN controller after reset.
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//!
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//! \param ui32Base is the base address of the CAN controller.
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//!
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//! After reset, the CAN controller is left in the disabled state. However,
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//! the memory used for message objects contains undefined values and must be
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//! cleared prior to enabling the CAN controller the first time. This prevents
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//! unwanted transmission or reception of data before the message objects are
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//! configured. This function must be called before enabling the controller
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//! the first time.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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CANInit(uint32_t ui32Base)
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{
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uint32_t ui32Msg;
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//
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// Check the arguments.
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//
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ASSERT(_CANBaseValid(ui32Base));
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//
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// Place CAN controller in init state, regardless of previous state. This
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// will put controller in idle, and allow the message object RAM to be
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// programmed.
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//
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HWREG(ui32Base + CAN_O_CTL) = CAN_CTL_INIT;
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//
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// Wait for busy bit to clear
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//
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while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
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{
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}
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//
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// Clear the message value bit in the arbitration register. This indicates
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// the message is not valid and is a "safe" condition to leave the message
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// object. The same arb reg is used to program all the message objects.
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//
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HWREG(ui32Base + CAN_O_IF1CMSK) = (CAN_IF1CMSK_WRNRD | CAN_IF1CMSK_ARB |
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CAN_IF1CMSK_CONTROL);
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HWREG(ui32Base + CAN_O_IF1ARB2) = 0;
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HWREG(ui32Base + CAN_O_IF1MCTL) = 0;
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//
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// Loop through to program all 32 message objects
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//
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for(ui32Msg = 1; ui32Msg <= 32; ui32Msg++)
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{
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//
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// Wait for busy bit to clear
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//
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while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
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{
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}
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//
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// Initiate programming the message object
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//
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HWREG(ui32Base + CAN_O_IF1CRQ) = ui32Msg;
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}
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//
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// Make sure that the interrupt and new data flags are updated for the
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// message objects.
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//
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HWREG(ui32Base + CAN_O_IF1CMSK) = (CAN_IF1CMSK_NEWDAT |
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CAN_IF1CMSK_CLRINTPND);
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//
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// Loop through to program all 32 message objects
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//
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for(ui32Msg = 1; ui32Msg <= 32; ui32Msg++)
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{
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//
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// Wait for busy bit to clear.
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//
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while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
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{
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}
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//
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// Initiate programming the message object
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//
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HWREG(ui32Base + CAN_O_IF1CRQ) = ui32Msg;
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}
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//
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// Acknowledge any pending status interrupts.
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//
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HWREG(ui32Base + CAN_O_STS);
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}
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//*****************************************************************************
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//
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//! Enables the CAN controller.
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//!
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//! \param ui32Base is the base address of the CAN controller to enable.
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//!
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//! Enables the CAN controller for message processing. Once enabled, the
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//! controller automatically transmits any pending frames, and processes any
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//! received frames. The controller can be stopped by calling CANDisable().
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//! Prior to calling CANEnable(), CANInit() should have been called to
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//! initialize the controller and the CAN bus clock should be configured by
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//! calling CANBitTimingSet().
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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CANEnable(uint32_t ui32Base)
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{
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//
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// Check the arguments.
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//
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ASSERT(_CANBaseValid(ui32Base));
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//
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// Clear the init bit in the control register.
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//
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HWREG(ui32Base + CAN_O_CTL) &= ~CAN_CTL_INIT;
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}
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//*****************************************************************************
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//
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//! Disables the CAN controller.
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//!
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//! \param ui32Base is the base address of the CAN controller to disable.
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//!
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//! Disables the CAN controller for message processing. When disabled, the
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//! controller no longer automatically processes data on the CAN bus. The
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//! controller can be restarted by calling CANEnable(). The state of the CAN
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//! controller and the message objects in the controller are left as they were
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//! before this call was made.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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CANDisable(uint32_t ui32Base)
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{
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//
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// Check the arguments.
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//
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ASSERT(_CANBaseValid(ui32Base));
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//
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// Set the init bit in the control register.
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//
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HWREG(ui32Base + CAN_O_CTL) |= CAN_CTL_INIT;
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}
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//*****************************************************************************
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//
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//! Reads the current settings for the CAN controller bit timing.
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//!
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//! \param ui32Base is the base address of the CAN controller.
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//! \param psClkParms is a pointer to a structure to hold the timing
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//! parameters.
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//!
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//! This function reads the current configuration of the CAN controller bit
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//! clock timing and stores the resulting information in the structure
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//! supplied by the caller. Refer to CANBitTimingSet() for the meaning of the
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//! values that are returned in the structure pointed to by \e psClkParms.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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CANBitTimingGet(uint32_t ui32Base, tCANBitClkParms *psClkParms)
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{
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uint32_t ui32BitReg;
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//
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// Check the arguments.
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//
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ASSERT(_CANBaseValid(ui32Base));
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ASSERT(psClkParms);
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//
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// Read out all the bit timing values from the CAN controller registers.
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//
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ui32BitReg = HWREG(ui32Base + CAN_O_BIT);
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//
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// Set the phase 2 segment.
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//
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psClkParms->ui32Phase2Seg =
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((ui32BitReg & CAN_BIT_TSEG2_M) >> CAN_BIT_TSEG2_S) + 1;
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//
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// Set the phase 1 segment.
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//
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psClkParms->ui32SyncPropPhase1Seg =
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((ui32BitReg & CAN_BIT_TSEG1_M) >> CAN_BIT_TSEG1_S) + 1;
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//
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// Set the synchronous jump width.
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//
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psClkParms->ui32SJW = ((ui32BitReg & CAN_BIT_SJW_M) >> CAN_BIT_SJW_S) + 1;
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//
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// Set the pre-divider for the CAN bus bit clock.
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//
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psClkParms->ui32QuantumPrescaler =
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((ui32BitReg & CAN_BIT_BRP_M) |
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((HWREG(ui32Base + CAN_O_BRPE) & CAN_BRPE_BRPE_M) << 6)) + 1;
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}
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|
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//*****************************************************************************
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//
|
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//! Sets the CAN bit timing values to a nominal setting based on a desired
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//! bit rate.
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//!
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//! \param ui32Base is the base address of the CAN controller.
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//! \param ui32SourceClock is the system clock for the device in Hz.
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//! \param ui32BitRate is the desired bit rate.
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//!
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//! This function sets the CAN bit timing for the bit rate passed in the
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//! \e ui32BitRate parameter based on the \e ui32SourceClock parameter.
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//! Because the CAN clock is based off of the system clock, the calling
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//! function should pass in the source clock rate either by retrieving it from
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//! SysCtlClockGet() or using a specific value in Hz. The CAN bit timing is
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//! calculated assuming a minimal amount of propagation delay, which works for
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//! most cases where the network length is int16_t. If tighter timing
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//! requirements or longer network lengths are needed, then the
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//! CANBitTimingSet() function is available for full customization of all of
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//! the CAN bit timing values. Because not all bit rates can be matched
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//! exactly, the bit rate is set to the value closest to the desired bit rate
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//! without being higher than the \e ui32BitRate value.
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|
//!
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//! \note On some devices the source clock is fixed at 8MHz so the
|
|
//! \e ui32SourceClock should be set to 8000000.
|
|
//!
|
|
//! \return This function returns the bit rate that the CAN controller was
|
|
//! configured to use or it returns 0 to indicate that the bit rate was not
|
|
//! changed because the requested bit rate was not valid.
|
|
//!
|
|
//*****************************************************************************
|
|
uint32_t
|
|
CANBitRateSet(uint32_t ui32Base, uint32_t ui32SourceClock,
|
|
uint32_t ui32BitRate)
|
|
{
|
|
uint32_t ui32DesiredRatio;
|
|
uint32_t ui32CANBits;
|
|
uint32_t ui32PreDivide;
|
|
uint32_t ui32RegValue;
|
|
uint16_t ui16CANCTL;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT(ui32SourceClock);
|
|
ASSERT(ui32BitRate);
|
|
|
|
//
|
|
// Calculate the desired clock rate.
|
|
//
|
|
ui32DesiredRatio = ui32SourceClock / ui32BitRate;
|
|
|
|
//
|
|
// Make sure that the ratio of CAN bit rate to processor clock is not too
|
|
// small or too large.
|
|
//
|
|
ASSERT(ui32DesiredRatio <= (CAN_MAX_PRE_DIVISOR * CAN_MAX_BIT_DIVISOR));
|
|
ASSERT(ui32DesiredRatio >= (CAN_MIN_PRE_DIVISOR * CAN_MIN_BIT_DIVISOR));
|
|
|
|
//
|
|
// Make sure that the Desired Ratio is not too large. This enforces the
|
|
// requirement that the bit rate is larger than requested.
|
|
//
|
|
if((ui32SourceClock / ui32DesiredRatio) > ui32BitRate)
|
|
{
|
|
ui32DesiredRatio += 1;
|
|
}
|
|
|
|
//
|
|
// Check all possible values to find a matching value.
|
|
//
|
|
while(ui32DesiredRatio <= (CAN_MAX_PRE_DIVISOR * CAN_MAX_BIT_DIVISOR))
|
|
{
|
|
//
|
|
// Loop through all possible CAN bit divisors.
|
|
//
|
|
for(ui32CANBits = CAN_MAX_BIT_DIVISOR;
|
|
ui32CANBits >= CAN_MIN_BIT_DIVISOR; ui32CANBits--)
|
|
{
|
|
//
|
|
// For a given CAN bit divisor save the pre divisor.
|
|
//
|
|
ui32PreDivide = ui32DesiredRatio / ui32CANBits;
|
|
|
|
//
|
|
// If the calculated divisors match the desired clock ratio then
|
|
// return these bit rate and set the CAN bit timing.
|
|
//
|
|
if((ui32PreDivide * ui32CANBits) == ui32DesiredRatio)
|
|
{
|
|
//
|
|
// Start building the bit timing value by adding the bit timing
|
|
// in time quanta.
|
|
//
|
|
ui32RegValue = g_ui16CANBitValues[ui32CANBits -
|
|
CAN_MIN_BIT_DIVISOR];
|
|
|
|
//
|
|
// To set the bit timing register, the controller must be
|
|
// placed in init mode (if not already), and also configuration
|
|
// change bit enabled. The state of the register should be
|
|
// saved so it can be restored.
|
|
//
|
|
ui16CANCTL = HWREG(ui32Base + CAN_O_CTL);
|
|
HWREG(ui32Base + CAN_O_CTL) = ui16CANCTL | CAN_CTL_INIT |
|
|
CAN_CTL_CCE;
|
|
|
|
//
|
|
// Now add in the pre-scalar on the bit rate.
|
|
//
|
|
ui32RegValue |= ((ui32PreDivide - 1) & CAN_BIT_BRP_M);
|
|
|
|
//
|
|
// Set the clock bits in the and the lower bits of the
|
|
// pre-scalar.
|
|
//
|
|
HWREG(ui32Base + CAN_O_BIT) = ui32RegValue;
|
|
|
|
//
|
|
// Set the divider upper bits in the extension register.
|
|
//
|
|
HWREG(ui32Base + CAN_O_BRPE) = ((ui32PreDivide - 1) >> 6) &
|
|
CAN_BRPE_BRPE_M;
|
|
|
|
//
|
|
// Restore the saved CAN Control register.
|
|
//
|
|
HWREG(ui32Base + CAN_O_CTL) = ui16CANCTL;
|
|
|
|
//
|
|
// Return the computed bit rate.
|
|
//
|
|
return(ui32SourceClock / (ui32PreDivide * ui32CANBits));
|
|
}
|
|
}
|
|
|
|
//
|
|
// Move the divisor up one and look again. Only in rare cases are
|
|
// more than 2 loops required to find the value.
|
|
//
|
|
ui32DesiredRatio++;
|
|
}
|
|
|
|
//
|
|
// A valid combination could not be found, so return 0 to indicate that the
|
|
// bit rate was not changed.
|
|
//
|
|
return(0);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures the CAN controller bit timing.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param psClkParms points to the structure with the clock parameters.
|
|
//!
|
|
//! Configures the various timing parameters for the CAN bus bit timing:
|
|
//! Propagation segment, Phase Buffer 1 segment, Phase Buffer 2 segment, and
|
|
//! the Synchronization Jump Width. The values for Propagation and Phase
|
|
//! Buffer 1 segments are derived from the combination
|
|
//! \e psClkParms->ui32SyncPropPhase1Seg parameter. Phase Buffer 2 is
|
|
//! determined from the \e psClkParms->ui32Phase2Seg parameter. These two
|
|
//! parameters, along with \e psClkParms->ui32SJW are based in units of bit
|
|
//! time quanta. The actual quantum time is determined by the
|
|
//! \e psClkParms->ui32QuantumPrescaler value, which specifies the divisor for
|
|
//! the CAN module clock.
|
|
//!
|
|
//! The total bit time, in quanta, is the sum of the two Seg parameters,
|
|
//! as follows:
|
|
//!
|
|
//! bit_time_q = ui32SyncPropPhase1Seg + ui32Phase2Seg + 1
|
|
//!
|
|
//! Note that the Sync_Seg is always one quantum in duration, and is added
|
|
//! to derive the correct duration of Prop_Seg and Phase1_Seg.
|
|
//!
|
|
//! The equation to determine the actual bit rate is as follows:
|
|
//!
|
|
//! CAN Clock /
|
|
//! ((\e ui32SyncPropPhase1Seg + \e ui32Phase2Seg + 1) *
|
|
//! (\e ui32QuantumPrescaler))
|
|
//!
|
|
//! Thus with \e ui32SyncPropPhase1Seg = 4, \e ui32Phase2Seg = 1,
|
|
//! \e ui32QuantumPrescaler = 2 and an 8 MHz CAN clock, the bit rate is
|
|
//! (8 MHz) / ((5 + 2 + 1) * 2) or 500 Kbit/sec.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANBitTimingSet(uint32_t ui32Base, tCANBitClkParms *psClkParms)
|
|
{
|
|
uint32_t ui32BitReg, ui32SavedInit;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT(psClkParms);
|
|
|
|
//
|
|
// The phase 1 segment must be in the range from 2 to 16.
|
|
//
|
|
ASSERT((psClkParms->ui32SyncPropPhase1Seg >= 2) &&
|
|
(psClkParms->ui32SyncPropPhase1Seg <= 16));
|
|
|
|
//
|
|
// The phase 2 segment must be in the range from 1 to 8.
|
|
//
|
|
ASSERT((psClkParms->ui32Phase2Seg >= 1) &&
|
|
(psClkParms->ui32Phase2Seg <= 8));
|
|
|
|
//
|
|
// The synchronous jump windows must be in the range from 1 to 4.
|
|
//
|
|
ASSERT((psClkParms->ui32SJW >= 1) && (psClkParms->ui32SJW <= 4));
|
|
|
|
//
|
|
// The CAN clock pre-divider must be in the range from 1 to 1024.
|
|
//
|
|
ASSERT((psClkParms->ui32QuantumPrescaler <= 1024) &&
|
|
(psClkParms->ui32QuantumPrescaler >= 1));
|
|
|
|
//
|
|
// To set the bit timing register, the controller must be placed in init
|
|
// mode (if not already), and also configuration change bit enabled. State
|
|
// of the init bit should be saved so it can be restored at the end.
|
|
//
|
|
ui32SavedInit = HWREG(ui32Base + CAN_O_CTL);
|
|
HWREG(ui32Base + CAN_O_CTL) = ui32SavedInit | CAN_CTL_INIT | CAN_CTL_CCE;
|
|
|
|
//
|
|
// Set the bit fields of the bit timing register according to the parms.
|
|
//
|
|
ui32BitReg = (((psClkParms->ui32Phase2Seg - 1) << CAN_BIT_TSEG2_S) &
|
|
CAN_BIT_TSEG2_M);
|
|
ui32BitReg |= (((psClkParms->ui32SyncPropPhase1Seg - 1) <<
|
|
CAN_BIT_TSEG1_S) & CAN_BIT_TSEG1_M);
|
|
ui32BitReg |= ((psClkParms->ui32SJW - 1) << CAN_BIT_SJW_S) & CAN_BIT_SJW_M;
|
|
ui32BitReg |= (psClkParms->ui32QuantumPrescaler - 1) & CAN_BIT_BRP_M;
|
|
HWREG(ui32Base + CAN_O_BIT) = ui32BitReg;
|
|
|
|
//
|
|
// Set the divider upper bits in the extension register.
|
|
//
|
|
HWREG(ui32Base + CAN_O_BRPE) =
|
|
((psClkParms->ui32QuantumPrescaler - 1) >> 6) & CAN_BRPE_BRPE_M;
|
|
|
|
//
|
|
// Clear the config change bit, and restore the init bit.
|
|
//
|
|
ui32SavedInit &= ~CAN_CTL_CCE;
|
|
|
|
//
|
|
// If Init was not set before, then clear it.
|
|
//
|
|
if(ui32SavedInit & CAN_CTL_INIT)
|
|
{
|
|
ui32SavedInit &= ~CAN_CTL_INIT;
|
|
}
|
|
|
|
HWREG(ui32Base + CAN_O_CTL) = ui32SavedInit;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Registers an interrupt handler for the CAN controller.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param pfnHandler is a pointer to the function to be called when the
|
|
//! enabled CAN interrupts occur.
|
|
//!
|
|
//! This function registers the interrupt handler in the interrupt vector
|
|
//! table, and enables CAN interrupts on the interrupt controller; specific CAN
|
|
//! interrupt sources must be enabled using CANIntEnable(). The interrupt
|
|
//! handler being registered must clear the source of the interrupt using
|
|
//! CANIntClear().
|
|
//!
|
|
//! If the application is using a static interrupt vector table stored in
|
|
//! flash, then it is not necessary to register the interrupt handler this way.
|
|
//! Instead, IntEnable() should be used to enable CAN interrupts on the
|
|
//! interrupt controller.
|
|
//!
|
|
//! \sa IntRegister() for important information about registering interrupt
|
|
//! handlers.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANIntRegister(uint32_t ui32Base, void (*pfnHandler)(void))
|
|
{
|
|
uint_fast8_t ui8IntNumber;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
//
|
|
// Get the actual interrupt number for this CAN controller.
|
|
//
|
|
ui8IntNumber = _CANIntNumberGet(ui32Base);
|
|
ASSERT(ui8IntNumber != 0);
|
|
|
|
//
|
|
// Register the interrupt handler.
|
|
//
|
|
IntRegister(ui8IntNumber, pfnHandler);
|
|
|
|
//
|
|
// Enable the Ethernet interrupt.
|
|
//
|
|
IntEnable(ui8IntNumber);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Unregisters an interrupt handler for the CAN controller.
|
|
//!
|
|
//! \param ui32Base is the base address of the controller.
|
|
//!
|
|
//! This function unregisters the previously registered interrupt handler and
|
|
//! disables the interrupt in the interrupt controller.
|
|
//!
|
|
//! \sa IntRegister() for important information about registering interrupt
|
|
//! handlers.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANIntUnregister(uint32_t ui32Base)
|
|
{
|
|
uint_fast8_t ui8IntNumber;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
//
|
|
// Get the actual interrupt number for this CAN controller.
|
|
//
|
|
ui8IntNumber = _CANIntNumberGet(ui32Base);
|
|
ASSERT(ui8IntNumber != 0);
|
|
|
|
//
|
|
// Disable the CAN interrupt.
|
|
//
|
|
IntDisable(ui8IntNumber);
|
|
|
|
//
|
|
// Register the interrupt handler.
|
|
//
|
|
IntUnregister(ui8IntNumber);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Enables individual CAN controller interrupt sources.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32IntFlags is the bit mask of the interrupt sources to be enabled.
|
|
//!
|
|
//! This function enables specific interrupt sources of the CAN controller.
|
|
//! Only enabled sources cause a processor interrupt.
|
|
//!
|
|
//! The \e ui32IntFlags parameter is the logical OR of any of the following:
|
|
//!
|
|
//! - \b CAN_INT_ERROR - a controller error condition has occurred
|
|
//! - \b CAN_INT_STATUS - a message transfer has completed, or a bus error has
|
|
//! been detected
|
|
//! - \b CAN_INT_MASTER - allow CAN controller to generate interrupts
|
|
//!
|
|
//! In order to generate any interrupts, \b CAN_INT_MASTER must be enabled.
|
|
//! Further, for any particular transaction from a message object to generate
|
|
//! an interrupt, that message object must have interrupts enabled (see
|
|
//! CANMessageSet()). \b CAN_INT_ERROR will generate an interrupt if the
|
|
//! controller enters the ``bus off'' condition, or if the error counters reach
|
|
//! a limit. \b CAN_INT_STATUS generates an interrupt under quite a few
|
|
//! status conditions and may provide more interrupts than the application
|
|
//! needs to handle. When an interrupt occurs, use CANIntStatus() to determine
|
|
//! the cause.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANIntEnable(uint32_t ui32Base, uint32_t ui32IntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32IntFlags & ~(CAN_CTL_EIE | CAN_CTL_SIE | CAN_CTL_IE)) == 0);
|
|
|
|
//
|
|
// Enable the specified interrupts.
|
|
//
|
|
HWREG(ui32Base + CAN_O_CTL) |= ui32IntFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Disables individual CAN controller interrupt sources.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32IntFlags is the bit mask of the interrupt sources to be
|
|
//! disabled.
|
|
//!
|
|
//! Disables the specified CAN controller interrupt sources. Only enabled
|
|
//! interrupt sources can cause a processor interrupt.
|
|
//!
|
|
//! The \e ui32IntFlags parameter has the same definition as in the
|
|
//! CANIntEnable() function.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANIntDisable(uint32_t ui32Base, uint32_t ui32IntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32IntFlags & ~(CAN_CTL_EIE | CAN_CTL_SIE | CAN_CTL_IE)) == 0);
|
|
|
|
//
|
|
// Disable the specified interrupts.
|
|
//
|
|
HWREG(ui32Base + CAN_O_CTL) &= ~ui32IntFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Returns the current CAN controller interrupt status.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param eIntStsReg indicates which interrupt status register to read
|
|
//!
|
|
//! This function returns the value of one of two interrupt status registers.
|
|
//! The interrupt status register read is determined by the \e eIntStsReg
|
|
//! parameter, which can have one of the following values:
|
|
//!
|
|
//! - \b CAN_INT_STS_CAUSE - indicates the cause of the interrupt
|
|
//! - \b CAN_INT_STS_OBJECT - indicates pending interrupts of all message
|
|
//! objects
|
|
//!
|
|
//! \b CAN_INT_STS_CAUSE returns the value of the controller interrupt register
|
|
//! and indicates the cause of the interrupt. The value returned is
|
|
//! \b CAN_INT_INTID_STATUS if the cause is a status interrupt. In this case,
|
|
//! the status register should be read with the CANStatusGet() function.
|
|
//! Calling this function to read the status also clears the status
|
|
//! interrupt. If the value of the interrupt register is in the range 1-32,
|
|
//! then this indicates the number of the highest priority message object that
|
|
//! has an interrupt pending. The message object interrupt can be cleared by
|
|
//! using the CANIntClear() function, or by reading the message using
|
|
//! CANMessageGet() in the case of a received message. The interrupt handler
|
|
//! can read the interrupt status again to make sure all pending interrupts are
|
|
//! cleared before returning from the interrupt.
|
|
//!
|
|
//! \b CAN_INT_STS_OBJECT returns a bit mask indicating which message objects
|
|
//! have pending interrupts. This value can be used to discover all of the
|
|
//! pending interrupts at once, as opposed to repeatedly reading the interrupt
|
|
//! register by using \b CAN_INT_STS_CAUSE.
|
|
//!
|
|
//! \return Returns the value of one of the interrupt status registers.
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
CANIntStatus(uint32_t ui32Base, tCANIntStsReg eIntStsReg)
|
|
{
|
|
uint32_t ui32Status;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
//
|
|
// See which status the caller is looking for.
|
|
//
|
|
switch(eIntStsReg)
|
|
{
|
|
//
|
|
// The caller wants the global interrupt status for the CAN controller
|
|
// specified by ui32Base.
|
|
//
|
|
case CAN_INT_STS_CAUSE:
|
|
{
|
|
ui32Status = HWREG(ui32Base + CAN_O_INT);
|
|
break;
|
|
}
|
|
|
|
//
|
|
// The caller wants the current message status interrupt for all
|
|
// messages.
|
|
//
|
|
case CAN_INT_STS_OBJECT:
|
|
{
|
|
//
|
|
// Read and combine both 16 bit values into one 32bit status.
|
|
//
|
|
ui32Status = (HWREG(ui32Base + CAN_O_MSG1INT) &
|
|
CAN_MSG1INT_INTPND_M);
|
|
ui32Status |= (HWREG(ui32Base + CAN_O_MSG2INT) << 16);
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Request was for unknown status so just return 0.
|
|
//
|
|
default:
|
|
{
|
|
ui32Status = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Return the interrupt status value
|
|
//
|
|
return(ui32Status);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Clears a CAN interrupt source.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32IntClr is a value indicating which interrupt source to clear.
|
|
//!
|
|
//! This function can be used to clear a specific interrupt source. The
|
|
//! \e ui32IntClr parameter should be one of the following values:
|
|
//!
|
|
//! - \b CAN_INT_INTID_STATUS - Clears a status interrupt.
|
|
//! - 1-32 - Clears the specified message object interrupt
|
|
//!
|
|
//! It is not necessary to use this function to clear an interrupt. This
|
|
//! function should only be used if the application wants to clear an interrupt
|
|
//! source without taking the normal interrupt action.
|
|
//!
|
|
//! Normally, the status interrupt is cleared by reading the controller status
|
|
//! using CANStatusGet(). A specific message object interrupt is normally
|
|
//! cleared by reading the message object using CANMessageGet().
|
|
//!
|
|
//! \note Because there is a write buffer in the Cortex-M processor, it may
|
|
//! take several clock cycles before the interrupt source is actually cleared.
|
|
//! Therefore, it is recommended that the interrupt source be cleared early in
|
|
//! the interrupt handler (as opposed to the very last action) to avoid
|
|
//! returning from the interrupt handler before the interrupt source is
|
|
//! actually cleared. Failure to do so may result in the interrupt handler
|
|
//! being immediately reentered (because the interrupt controller still sees
|
|
//! the interrupt source asserted).
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANIntClear(uint32_t ui32Base, uint32_t ui32IntClr)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32IntClr == CAN_INT_INTID_STATUS) ||
|
|
((ui32IntClr >= 1) && (ui32IntClr <= 32)));
|
|
|
|
if(ui32IntClr == CAN_INT_INTID_STATUS)
|
|
{
|
|
//
|
|
// Simply read and discard the status to clear the interrupt.
|
|
//
|
|
HWREG(ui32Base + CAN_O_STS);
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Wait to be sure that this interface is not busy.
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
|
|
//
|
|
// Only change the interrupt pending state by setting only the
|
|
// CAN_IF1CMSK_CLRINTPND bit.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CMSK) = CAN_IF1CMSK_CLRINTPND;
|
|
|
|
//
|
|
// Send the clear pending interrupt command to the CAN controller.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CRQ) = ui32IntClr & CAN_IF1CRQ_MNUM_M;
|
|
|
|
//
|
|
// Wait to be sure that this interface is not busy.
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Sets the CAN controller automatic retransmission behavior.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param bAutoRetry enables automatic retransmission.
|
|
//!
|
|
//! This function enables or disables automatic retransmission of messages with
|
|
//! detected errors. If \e bAutoRetry is \b true, then automatic
|
|
//! retransmission is enabled, otherwise it is disabled.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANRetrySet(uint32_t ui32Base, bool bAutoRetry)
|
|
{
|
|
uint32_t ui32CtlReg;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
ui32CtlReg = HWREG(ui32Base + CAN_O_CTL);
|
|
|
|
//
|
|
// Conditionally set the DAR bit to enable/disable auto-retry.
|
|
//
|
|
if(bAutoRetry)
|
|
{
|
|
//
|
|
// Clearing the DAR bit tells the controller to not disable the
|
|
// auto-retry of messages which were not transmitted or received
|
|
// correctly.
|
|
//
|
|
ui32CtlReg &= ~CAN_CTL_DAR;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Setting the DAR bit tells the controller to disable the auto-retry
|
|
// of messages which were not transmitted or received correctly.
|
|
//
|
|
ui32CtlReg |= CAN_CTL_DAR;
|
|
}
|
|
|
|
HWREG(ui32Base + CAN_O_CTL) = ui32CtlReg;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Returns the current setting for automatic retransmission.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//!
|
|
//! This function reads the current setting for automatic retransmission in the
|
|
//! CAN controller and returns it to the caller.
|
|
//!
|
|
//! \return Returns \b true if automatic retransmission is enabled, \b false
|
|
//! otherwise.
|
|
//
|
|
//*****************************************************************************
|
|
bool
|
|
CANRetryGet(uint32_t ui32Base)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
//
|
|
// Read the disable automatic retry setting from the CAN controller.
|
|
//
|
|
if(HWREG(ui32Base + CAN_O_CTL) & CAN_CTL_DAR)
|
|
{
|
|
//
|
|
// Automatic data retransmission is not enabled.
|
|
//
|
|
return(false);
|
|
}
|
|
|
|
//
|
|
// Automatic data retransmission is enabled.
|
|
//
|
|
return(true);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Reads one of the controller status registers.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param eStatusReg is the status register to read.
|
|
//!
|
|
//! This function reads a status register of the CAN controller and returns it
|
|
//! to the caller.
|
|
//! The different status registers are:
|
|
//!
|
|
//! - \b CAN_STS_CONTROL - the main controller status
|
|
//! - \b CAN_STS_TXREQUEST - bit mask of objects pending transmission
|
|
//! - \b CAN_STS_NEWDAT - bit mask of objects with new data
|
|
//! - \b CAN_STS_MSGVAL - bit mask of objects with valid configuration
|
|
//!
|
|
//! When reading the main controller status register, a pending status
|
|
//! interrupt is cleared. This parameter should be used in the interrupt
|
|
//! handler for the CAN controller if the cause is a status interrupt. The
|
|
//! controller status register fields are as follows:
|
|
//!
|
|
//! - \b CAN_STATUS_BUS_OFF - controller is in bus-off condition
|
|
//! - \b CAN_STATUS_EWARN - an error counter has reached a limit of at least 96
|
|
//! - \b CAN_STATUS_EPASS - CAN controller is in the error passive state
|
|
//! - \b CAN_STATUS_RXOK - a message was received successfully (independent of
|
|
//! any message filtering).
|
|
//! - \b CAN_STATUS_TXOK - a message was successfully transmitted
|
|
//! - \b CAN_STATUS_LEC_MSK - mask of last error code bits (3 bits)
|
|
//! - \b CAN_STATUS_LEC_NONE - no error
|
|
//! - \b CAN_STATUS_LEC_STUFF - stuffing error detected
|
|
//! - \b CAN_STATUS_LEC_FORM - a format error occurred in the fixed format part
|
|
//! of a message
|
|
//! - \b CAN_STATUS_LEC_ACK - a transmitted message was not acknowledged
|
|
//! - \b CAN_STATUS_LEC_BIT1 - dominant level detected when trying to send in
|
|
//! recessive mode
|
|
//! - \b CAN_STATUS_LEC_BIT0 - recessive level detected when trying to send in
|
|
//! dominant mode
|
|
//! - \b CAN_STATUS_LEC_CRC - CRC error in received message
|
|
//!
|
|
//! The remaining status registers consist of 32-bit-wide bit maps to the
|
|
//! message objects. They can be used to quickly obtain information about the
|
|
//! status of all the message objects without needing to query each one. They
|
|
//! contain the following information:
|
|
//!
|
|
//! - \b CAN_STS_TXREQUEST - if a message object's TXRQST bit is set, a
|
|
//! transmission is pending on that object. The application can use this
|
|
//! information to determine which objects are still waiting to send a
|
|
//! message.
|
|
//! - \b CAN_STS_NEWDAT - if a message object's NEWDAT bit is set, a new
|
|
//! message has been received in that object, and has not yet been picked up
|
|
//! by the host application
|
|
//! - \b CAN_STS_MSGVAL - if a message object's MSGVAL bit is set, the object
|
|
//! has a valid configuration programmed. The host application can use this
|
|
//! information to determine which message objects are empty/unused.
|
|
//!
|
|
//! \return Returns the value of the status register.
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
CANStatusGet(uint32_t ui32Base, tCANStsReg eStatusReg)
|
|
{
|
|
uint32_t ui32Status;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
switch(eStatusReg)
|
|
{
|
|
//
|
|
// Just return the global CAN status register since that is what was
|
|
// requested.
|
|
//
|
|
case CAN_STS_CONTROL:
|
|
{
|
|
ui32Status = HWREG(ui32Base + CAN_O_STS);
|
|
HWREG(ui32Base + CAN_O_STS) = ~(CAN_STS_RXOK | CAN_STS_TXOK |
|
|
CAN_STS_LEC_M);
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Combine the Transmit status bits into one 32bit value.
|
|
//
|
|
case CAN_STS_TXREQUEST:
|
|
{
|
|
ui32Status = HWREG(ui32Base + CAN_O_TXRQ1);
|
|
ui32Status |= HWREG(ui32Base + CAN_O_TXRQ2) << 16;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Combine the New Data status bits into one 32bit value.
|
|
//
|
|
case CAN_STS_NEWDAT:
|
|
{
|
|
ui32Status = HWREG(ui32Base + CAN_O_NWDA1);
|
|
ui32Status |= HWREG(ui32Base + CAN_O_NWDA2) << 16;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Combine the Message valid status bits into one 32bit value.
|
|
//
|
|
case CAN_STS_MSGVAL:
|
|
{
|
|
ui32Status = HWREG(ui32Base + CAN_O_MSG1VAL);
|
|
ui32Status |= HWREG(ui32Base + CAN_O_MSG2VAL) << 16;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Unknown CAN status requested so return 0.
|
|
//
|
|
default:
|
|
{
|
|
ui32Status = 0;
|
|
break;
|
|
}
|
|
}
|
|
return(ui32Status);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Reads the CAN controller error counter register.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param pui32RxCount is a pointer to storage for the receive error counter.
|
|
//! \param pui32TxCount is a pointer to storage for the transmit error counter.
|
|
//!
|
|
//! This function reads the error counter register and returns the transmit and
|
|
//! receive error counts to the caller along with a flag indicating if the
|
|
//! controller receive counter has reached the error passive limit. The values
|
|
//! of the receive and transmit error counters are returned through the
|
|
//! pointers provided as parameters.
|
|
//!
|
|
//! After this call, \e *pui32RxCount holds the current receive error count
|
|
//! and \e *pui32TxCount holds the current transmit error count.
|
|
//!
|
|
//! \return Returns \b true if the receive error count has reached the error
|
|
//! passive limit, and \b false if the error count is below the error passive
|
|
//! limit.
|
|
//
|
|
//*****************************************************************************
|
|
bool
|
|
CANErrCntrGet(uint32_t ui32Base, uint32_t *pui32RxCount,
|
|
uint32_t *pui32TxCount)
|
|
{
|
|
uint32_t ui32CANError;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
|
|
//
|
|
// Read the current count of transmit/receive errors.
|
|
//
|
|
ui32CANError = HWREG(ui32Base + CAN_O_ERR);
|
|
|
|
//
|
|
// Extract the error numbers from the register value.
|
|
//
|
|
*pui32RxCount = (ui32CANError & CAN_ERR_REC_M) >> CAN_ERR_REC_S;
|
|
*pui32TxCount = (ui32CANError & CAN_ERR_TEC_M) >> CAN_ERR_TEC_S;
|
|
|
|
if(ui32CANError & CAN_ERR_RP)
|
|
{
|
|
return(true);
|
|
}
|
|
return(false);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures a message object in the CAN controller.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32ObjID is the object number to configure (1-32).
|
|
//! \param psMsgObject is a pointer to a structure containing message object
|
|
//! settings.
|
|
//! \param eMsgType indicates the type of message for this object.
|
|
//!
|
|
//! This function is used to configure any one of the 32 message objects in the
|
|
//! CAN controller. A message object can be configured to be any type of CAN
|
|
//! message object as well as to use automatic transmission and reception.
|
|
//! This call also allows the message object to be configured to generate
|
|
//! interrupts on completion of message receipt or transmission. The
|
|
//! message object can also be configured with a filter/mask so that actions
|
|
//! are only taken when a message that meets certain parameters is seen on the
|
|
//! CAN bus.
|
|
//!
|
|
//! The \e eMsgType parameter must be one of the following values:
|
|
//!
|
|
//! - \b MSG_OBJ_TYPE_TX - CAN transmit message object.
|
|
//! - \b MSG_OBJ_TYPE_TX_REMOTE - CAN transmit remote request message object.
|
|
//! - \b MSG_OBJ_TYPE_RX - CAN receive message object.
|
|
//! - \b MSG_OBJ_TYPE_RX_REMOTE - CAN receive remote request message object.
|
|
//! - \b MSG_OBJ_TYPE_RXTX_REMOTE - CAN remote frame receive remote, then
|
|
//! transmit message object.
|
|
//!
|
|
//! The message object pointed to by \e psMsgObject must be populated by the
|
|
//! caller, as follows:
|
|
//!
|
|
//! - \e ui32MsgID - contains the message ID, either 11 or 29 bits.
|
|
//! - \e ui32MsgIDMask - mask of bits from \e ui32MsgID that must match if
|
|
//! identifier filtering is enabled.
|
|
//! - \e ui32Flags
|
|
//! - Set \b MSG_OBJ_TX_INT_ENABLE flag to enable interrupt on transmission.
|
|
//! - Set \b MSG_OBJ_RX_INT_ENABLE flag to enable interrupt on receipt.
|
|
//! - Set \b MSG_OBJ_USE_ID_FILTER flag to enable filtering based on the
|
|
//! identifier mask specified by \e ui32MsgIDMask.
|
|
//! - \e ui32MsgLen - the number of bytes in the message data. This parameter
|
|
//! should be non-zero even for a remote frame; it should match the expected
|
|
//! bytes of data in the responding data frame.
|
|
//! - \e pui8MsgData - points to a buffer containing up to 8 bytes of data for
|
|
//! a data frame.
|
|
//!
|
|
//! \b Example: To send a data frame or remote frame (in response to a remote
|
|
//! request), take the following steps:
|
|
//!
|
|
//! -# Set \e eMsgType to \b MSG_OBJ_TYPE_TX.
|
|
//! -# Set \e psMsgObject->ui32MsgID to the message ID.
|
|
//! -# Set \e psMsgObject->ui32Flags. Make sure to set
|
|
//! \b MSG_OBJ_TX_INT_ENABLE to allow an interrupt to be generated when the
|
|
//! message is sent.
|
|
//! -# Set \e psMsgObject->ui32MsgLen to the number of bytes in the data frame.
|
|
//! -# Set \e psMsgObject->pui8MsgData to point to an array containing the
|
|
//! bytes to send in the message.
|
|
//! -# Call this function with \e ui32ObjID set to one of the 32 object
|
|
//! buffers.
|
|
//!
|
|
//! \b Example: To receive a specific data frame, take the following steps:
|
|
//!
|
|
//! -# Set \e eMsgObjType to \b MSG_OBJ_TYPE_RX.
|
|
//! -# Set \e psMsgObject->ui32MsgID to the full message ID, or a partial mask
|
|
//! to use partial ID matching.
|
|
//! -# Set \e psMsgObject->ui32MsgIDMask bits that should be used for masking
|
|
//! during comparison.
|
|
//! -# Set \e psMsgObject->ui32Flags as follows:
|
|
//! - Set \b MSG_OBJ_RX_INT_ENABLE flag to be interrupted when the data
|
|
//! frame is received.
|
|
//! - Set \b MSG_OBJ_USE_ID_FILTER flag to enable identifier-based
|
|
//! filtering.
|
|
//! -# Set \e psMsgObject->ui32MsgLen to the number of bytes in the expected
|
|
//! data frame.
|
|
//! -# The buffer pointed to by \e psMsgObject->pui8MsgData is not used by this
|
|
//! call as no data is present at the time of the call.
|
|
//! -# Call this function with \e ui32ObjID set to one of the 32 object
|
|
//! buffers.
|
|
//!
|
|
//! If you specify a message object buffer that already contains a message
|
|
//! definition, it is overwritten.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANMessageSet(uint32_t ui32Base, uint32_t ui32ObjID,
|
|
tCANMsgObject *psMsgObject, tMsgObjType eMsgType)
|
|
{
|
|
uint16_t ui16CmdMaskReg;
|
|
uint16_t ui16MaskReg0, ui16MaskReg1;
|
|
uint16_t ui16ArbReg0, ui16ArbReg1;
|
|
uint16_t ui16MsgCtrl;
|
|
bool bTransferData;
|
|
bool bUseExtendedID;
|
|
|
|
bTransferData = 0;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32ObjID <= 32) && (ui32ObjID != 0));
|
|
ASSERT((eMsgType == MSG_OBJ_TYPE_TX) ||
|
|
(eMsgType == MSG_OBJ_TYPE_TX_REMOTE) ||
|
|
(eMsgType == MSG_OBJ_TYPE_RX) ||
|
|
(eMsgType == MSG_OBJ_TYPE_RX_REMOTE) ||
|
|
(eMsgType == MSG_OBJ_TYPE_TX_REMOTE) ||
|
|
(eMsgType == MSG_OBJ_TYPE_RXTX_REMOTE));
|
|
|
|
//
|
|
// Wait for busy bit to clear
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
|
|
//
|
|
// See if we need to use an extended identifier or not.
|
|
//
|
|
if((psMsgObject->ui32MsgID > CAN_MAX_11BIT_MSG_ID) ||
|
|
(psMsgObject->ui32Flags & MSG_OBJ_EXTENDED_ID))
|
|
{
|
|
bUseExtendedID = 1;
|
|
}
|
|
else
|
|
{
|
|
bUseExtendedID = 0;
|
|
}
|
|
|
|
//
|
|
// This is always a write to the Message object as this call is setting a
|
|
// message object. This call will also always set all size bits so it sets
|
|
// both data bits. The call will use the CONTROL register to set control
|
|
// bits so this bit needs to be set as well.
|
|
//
|
|
ui16CmdMaskReg = (CAN_IF1CMSK_WRNRD | CAN_IF1CMSK_DATAA |
|
|
CAN_IF1CMSK_DATAB | CAN_IF1CMSK_CONTROL);
|
|
|
|
//
|
|
// Initialize the values to a known state before filling them in based on
|
|
// the type of message object that is being configured.
|
|
//
|
|
ui16ArbReg0 = 0;
|
|
ui16ArbReg1 = 0;
|
|
ui16MsgCtrl = 0;
|
|
ui16MaskReg0 = 0;
|
|
ui16MaskReg1 = 0;
|
|
|
|
switch(eMsgType)
|
|
{
|
|
//
|
|
// Transmit message object.
|
|
//
|
|
case MSG_OBJ_TYPE_TX:
|
|
{
|
|
//
|
|
// Set the TXRQST bit and the reset the rest of the register.
|
|
//
|
|
ui16MsgCtrl |= CAN_IF1MCTL_TXRQST;
|
|
ui16ArbReg1 = CAN_IF1ARB2_DIR;
|
|
bTransferData = 1;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Transmit remote request message object
|
|
//
|
|
case MSG_OBJ_TYPE_TX_REMOTE:
|
|
{
|
|
//
|
|
// Set the TXRQST bit and the reset the rest of the register.
|
|
//
|
|
ui16MsgCtrl |= CAN_IF1MCTL_TXRQST;
|
|
ui16ArbReg1 = 0;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Receive message object.
|
|
//
|
|
case MSG_OBJ_TYPE_RX:
|
|
{
|
|
//
|
|
// This clears the DIR bit along with everything else. The TXRQST
|
|
// bit was cleared by defaulting ui16MsgCtrl to 0.
|
|
//
|
|
ui16ArbReg1 = 0;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Receive remote request message object.
|
|
//
|
|
case MSG_OBJ_TYPE_RX_REMOTE:
|
|
{
|
|
//
|
|
// The DIR bit is set to one for remote receivers. The TXRQST bit
|
|
// was cleared by defaulting ui16MsgCtrl to 0.
|
|
//
|
|
ui16ArbReg1 = CAN_IF1ARB2_DIR;
|
|
|
|
//
|
|
// Set this object so that it only indicates that a remote frame
|
|
// was received and allow for software to handle it by sending back
|
|
// a data frame.
|
|
//
|
|
ui16MsgCtrl = CAN_IF1MCTL_UMASK;
|
|
|
|
//
|
|
// Use the full Identifier by default.
|
|
//
|
|
ui16MaskReg0 = 0xffff;
|
|
ui16MaskReg1 = 0x1fff;
|
|
|
|
//
|
|
// Make sure to send the mask to the message object.
|
|
//
|
|
ui16CmdMaskReg |= CAN_IF1CMSK_MASK;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// Remote frame receive remote, with auto-transmit message object.
|
|
//
|
|
case MSG_OBJ_TYPE_RXTX_REMOTE:
|
|
{
|
|
//
|
|
// Oddly the DIR bit is set to one for remote receivers.
|
|
//
|
|
ui16ArbReg1 = CAN_IF1ARB2_DIR;
|
|
|
|
//
|
|
// Set this object to auto answer if a matching identifier is seen.
|
|
//
|
|
ui16MsgCtrl = CAN_IF1MCTL_RMTEN | CAN_IF1MCTL_UMASK;
|
|
|
|
//
|
|
// The data to be returned needs to be filled in.
|
|
//
|
|
bTransferData = 1;
|
|
break;
|
|
}
|
|
|
|
//
|
|
// This case should never happen due to the ASSERT statement at the
|
|
// beginning of this function.
|
|
//
|
|
default:
|
|
{
|
|
return;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Configure the Mask Registers.
|
|
//
|
|
if(psMsgObject->ui32Flags & MSG_OBJ_USE_ID_FILTER)
|
|
{
|
|
if(bUseExtendedID)
|
|
{
|
|
//
|
|
// Set the 29 bits of Identifier mask that were requested.
|
|
//
|
|
ui16MaskReg0 = psMsgObject->ui32MsgIDMask & CAN_IF1MSK1_IDMSK_M;
|
|
ui16MaskReg1 = ((psMsgObject->ui32MsgIDMask >> 16) &
|
|
CAN_IF1MSK2_IDMSK_M);
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Lower 16 bit are unused so set them to zero.
|
|
//
|
|
ui16MaskReg0 = 0;
|
|
|
|
//
|
|
// Put the 11 bit Mask Identifier into the upper bits of the field
|
|
// in the register.
|
|
//
|
|
ui16MaskReg1 = ((psMsgObject->ui32MsgIDMask << 2) &
|
|
CAN_IF1MSK2_IDMSK_M);
|
|
}
|
|
}
|
|
|
|
//
|
|
// If the caller wants to filter on the extended ID bit then set it.
|
|
//
|
|
if((psMsgObject->ui32Flags & MSG_OBJ_USE_EXT_FILTER) ==
|
|
MSG_OBJ_USE_EXT_FILTER)
|
|
{
|
|
ui16MaskReg1 |= CAN_IF1MSK2_MXTD;
|
|
}
|
|
|
|
//
|
|
// The caller wants to filter on the message direction field.
|
|
//
|
|
if((psMsgObject->ui32Flags & MSG_OBJ_USE_DIR_FILTER) ==
|
|
MSG_OBJ_USE_DIR_FILTER)
|
|
{
|
|
ui16MaskReg1 |= CAN_IF1MSK2_MDIR;
|
|
}
|
|
|
|
if(psMsgObject->ui32Flags &
|
|
(MSG_OBJ_USE_ID_FILTER | MSG_OBJ_USE_DIR_FILTER |
|
|
MSG_OBJ_USE_EXT_FILTER))
|
|
{
|
|
//
|
|
// Set the UMASK bit to enable using the mask register.
|
|
//
|
|
ui16MsgCtrl |= CAN_IF1MCTL_UMASK;
|
|
|
|
//
|
|
// Set the MASK bit so that this gets transferred to the Message
|
|
// Object.
|
|
//
|
|
ui16CmdMaskReg |= CAN_IF1CMSK_MASK;
|
|
}
|
|
|
|
//
|
|
// Set the Arb bit so that this gets transferred to the Message object.
|
|
//
|
|
ui16CmdMaskReg |= CAN_IF1CMSK_ARB;
|
|
|
|
//
|
|
// Configure the Arbitration registers.
|
|
//
|
|
if(bUseExtendedID)
|
|
{
|
|
//
|
|
// Set the 29 bit version of the Identifier for this message object.
|
|
//
|
|
ui16ArbReg0 |= psMsgObject->ui32MsgID & CAN_IF1ARB1_ID_M;
|
|
ui16ArbReg1 |= (psMsgObject->ui32MsgID >> 16) & CAN_IF1ARB2_ID_M;
|
|
|
|
//
|
|
// Mark the message as valid and set the extended ID bit.
|
|
//
|
|
ui16ArbReg1 |= CAN_IF1ARB2_MSGVAL | CAN_IF1ARB2_XTD;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Set the 11 bit version of the Identifier for this message object.
|
|
// The lower 18 bits are set to zero.
|
|
//
|
|
ui16ArbReg1 |= (psMsgObject->ui32MsgID << 2) & CAN_IF1ARB2_ID_M;
|
|
|
|
//
|
|
// Mark the message as valid.
|
|
//
|
|
ui16ArbReg1 |= CAN_IF1ARB2_MSGVAL;
|
|
}
|
|
|
|
//
|
|
// Set the data length since this is set for all transfers. This is also a
|
|
// single transfer and not a FIFO transfer so set EOB bit.
|
|
//
|
|
ui16MsgCtrl |= (psMsgObject->ui32MsgLen & CAN_IF1MCTL_DLC_M);
|
|
|
|
//
|
|
// Mark this as the last entry if this is not the last entry in a FIFO.
|
|
//
|
|
if((psMsgObject->ui32Flags & MSG_OBJ_FIFO) == 0)
|
|
{
|
|
ui16MsgCtrl |= CAN_IF1MCTL_EOB;
|
|
}
|
|
|
|
//
|
|
// Enable transmit interrupts if they should be enabled.
|
|
//
|
|
if(psMsgObject->ui32Flags & MSG_OBJ_TX_INT_ENABLE)
|
|
{
|
|
ui16MsgCtrl |= CAN_IF1MCTL_TXIE;
|
|
}
|
|
|
|
//
|
|
// Enable receive interrupts if they should be enabled.
|
|
//
|
|
if(psMsgObject->ui32Flags & MSG_OBJ_RX_INT_ENABLE)
|
|
{
|
|
ui16MsgCtrl |= CAN_IF1MCTL_RXIE;
|
|
}
|
|
|
|
//
|
|
// Write the data out to the CAN Data registers if needed.
|
|
//
|
|
if(bTransferData)
|
|
{
|
|
_CANDataRegWrite(psMsgObject->pui8MsgData,
|
|
(uint32_t *)(ui32Base + CAN_O_IF1DA1),
|
|
psMsgObject->ui32MsgLen);
|
|
}
|
|
|
|
//
|
|
// Write out the registers to program the message object.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CMSK) = ui16CmdMaskReg;
|
|
HWREG(ui32Base + CAN_O_IF1MSK1) = ui16MaskReg0;
|
|
HWREG(ui32Base + CAN_O_IF1MSK2) = ui16MaskReg1;
|
|
HWREG(ui32Base + CAN_O_IF1ARB1) = ui16ArbReg0;
|
|
HWREG(ui32Base + CAN_O_IF1ARB2) = ui16ArbReg1;
|
|
HWREG(ui32Base + CAN_O_IF1MCTL) = ui16MsgCtrl;
|
|
|
|
//
|
|
// Transfer the message object to the message object specified by
|
|
// ui32ObjID.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CRQ) = ui32ObjID & CAN_IF1CRQ_MNUM_M;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Reads a CAN message from one of the message object buffers.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32ObjID is the object number to read (1-32).
|
|
//! \param psMsgObject points to a structure containing message object fields.
|
|
//! \param bClrPendingInt indicates whether an associated interrupt should be
|
|
//! cleared.
|
|
//!
|
|
//! This function is used to read the contents of one of the 32 message objects
|
|
//! in the CAN controller and return it to the caller. The data returned is
|
|
//! stored in the fields of the caller-supplied structure pointed to by
|
|
//! \e psMsgObject. The data consists of all of the parts of a CAN message,
|
|
//! plus some control and status information.
|
|
//!
|
|
//! Normally, this function is used to read a message object that has received
|
|
//! and stored a CAN message with a certain identifier. However, this function
|
|
//! could also be used to read the contents of a message object in order to
|
|
//! load the fields of the structure in case only part of the structure must
|
|
//! be changed from a previous setting.
|
|
//!
|
|
//! When using CANMessageGet(), all of the same fields of the structure are
|
|
//! populated in the same way as when the CANMessageSet() function is used,
|
|
//! with the following exceptions:
|
|
//!
|
|
//! \e psMsgObject->ui32Flags:
|
|
//!
|
|
//! - \b MSG_OBJ_NEW_DATA indicates if this data is new since the last time it
|
|
//! was read
|
|
//! - \b MSG_OBJ_DATA_LOST indicates that at least one message was received on
|
|
//! this message object and not read by the host before being overwritten.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANMessageGet(uint32_t ui32Base, uint32_t ui32ObjID,
|
|
tCANMsgObject *psMsgObject, bool bClrPendingInt)
|
|
{
|
|
uint16_t ui16CmdMaskReg;
|
|
uint16_t ui16MaskReg0, ui16MaskReg1;
|
|
uint16_t ui16ArbReg0, ui16ArbReg1;
|
|
uint16_t ui16MsgCtrl;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32ObjID <= 32) && (ui32ObjID != 0));
|
|
|
|
//
|
|
// This is always a read to the Message object as this call is setting a
|
|
// message object.
|
|
//
|
|
ui16CmdMaskReg = (CAN_IF1CMSK_DATAA | CAN_IF1CMSK_DATAB |
|
|
CAN_IF1CMSK_CONTROL | CAN_IF1CMSK_MASK |
|
|
CAN_IF1CMSK_ARB);
|
|
|
|
//
|
|
// Clear a pending interrupt and new data in a message object.
|
|
//
|
|
if(bClrPendingInt)
|
|
{
|
|
ui16CmdMaskReg |= CAN_IF1CMSK_CLRINTPND;
|
|
}
|
|
|
|
//
|
|
// Set up the request for data from the message object.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF2CMSK) = ui16CmdMaskReg;
|
|
|
|
//
|
|
// Transfer the message object to the message object specified by
|
|
// ui32ObjID.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF2CRQ) = ui32ObjID & CAN_IF1CRQ_MNUM_M;
|
|
|
|
//
|
|
// Wait for busy bit to clear
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF2CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
|
|
//
|
|
// Read out the IF Registers.
|
|
//
|
|
ui16MaskReg0 = HWREG(ui32Base + CAN_O_IF2MSK1);
|
|
ui16MaskReg1 = HWREG(ui32Base + CAN_O_IF2MSK2);
|
|
ui16ArbReg0 = HWREG(ui32Base + CAN_O_IF2ARB1);
|
|
ui16ArbReg1 = HWREG(ui32Base + CAN_O_IF2ARB2);
|
|
ui16MsgCtrl = HWREG(ui32Base + CAN_O_IF2MCTL);
|
|
|
|
psMsgObject->ui32Flags = MSG_OBJ_NO_FLAGS;
|
|
|
|
//
|
|
// Determine if this is a remote frame by checking the TXRQST and DIR bits.
|
|
//
|
|
if((!(ui16MsgCtrl & CAN_IF1MCTL_TXRQST) &&
|
|
(ui16ArbReg1 & CAN_IF1ARB2_DIR)) ||
|
|
((ui16MsgCtrl & CAN_IF1MCTL_TXRQST) &&
|
|
(!(ui16ArbReg1 & CAN_IF1ARB2_DIR))))
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_REMOTE_FRAME;
|
|
}
|
|
|
|
//
|
|
// Get the identifier out of the register, the format depends on size of
|
|
// the mask.
|
|
//
|
|
if(ui16ArbReg1 & CAN_IF1ARB2_XTD)
|
|
{
|
|
//
|
|
// Set the 29 bit version of the Identifier for this message object.
|
|
//
|
|
psMsgObject->ui32MsgID = (((ui16ArbReg1 & CAN_IF1ARB2_ID_M) << 16) |
|
|
ui16ArbReg0);
|
|
|
|
psMsgObject->ui32Flags |= MSG_OBJ_EXTENDED_ID;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// The Identifier is an 11 bit value.
|
|
//
|
|
psMsgObject->ui32MsgID = (ui16ArbReg1 & CAN_IF1ARB2_ID_M) >> 2;
|
|
}
|
|
|
|
//
|
|
// Indicate that we lost some data.
|
|
//
|
|
if(ui16MsgCtrl & CAN_IF1MCTL_MSGLST)
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_DATA_LOST;
|
|
}
|
|
|
|
//
|
|
// Set the flag to indicate if ID masking was used.
|
|
//
|
|
if(ui16MsgCtrl & CAN_IF1MCTL_UMASK)
|
|
{
|
|
if(ui16ArbReg1 & CAN_IF1ARB2_XTD)
|
|
{
|
|
//
|
|
// The Identifier Mask is assumed to also be a 29 bit value.
|
|
//
|
|
psMsgObject->ui32MsgIDMask =
|
|
((ui16MaskReg1 & CAN_IF1MSK2_IDMSK_M) << 16) | ui16MaskReg0;
|
|
|
|
//
|
|
// If this is a fully specified Mask and a remote frame then don't
|
|
// set the MSG_OBJ_USE_ID_FILTER because the ID was not really
|
|
// filtered.
|
|
//
|
|
if((psMsgObject->ui32MsgIDMask != 0x1fffffff) ||
|
|
((psMsgObject->ui32Flags & MSG_OBJ_REMOTE_FRAME) == 0))
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_USE_ID_FILTER;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// The Identifier Mask is assumed to also be an 11 bit value.
|
|
//
|
|
psMsgObject->ui32MsgIDMask =
|
|
(ui16MaskReg1 & CAN_IF1MSK2_IDMSK_M) >> 2;
|
|
|
|
//
|
|
// If this is a fully specified Mask and a remote frame then don't
|
|
// set the MSG_OBJ_USE_ID_FILTER because the ID was not really
|
|
// filtered.
|
|
//
|
|
if((psMsgObject->ui32MsgIDMask != 0x7ff) ||
|
|
((psMsgObject->ui32Flags & MSG_OBJ_REMOTE_FRAME) == 0))
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_USE_ID_FILTER;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Indicate if the extended bit was used in filtering.
|
|
//
|
|
if(ui16MaskReg1 & CAN_IF1MSK2_MXTD)
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_USE_EXT_FILTER;
|
|
}
|
|
|
|
//
|
|
// Indicate if direction filtering was enabled.
|
|
//
|
|
if(ui16MaskReg1 & CAN_IF1MSK2_MDIR)
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_USE_DIR_FILTER;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Set the interrupt flags.
|
|
//
|
|
if(ui16MsgCtrl & CAN_IF1MCTL_TXIE)
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_TX_INT_ENABLE;
|
|
}
|
|
if(ui16MsgCtrl & CAN_IF1MCTL_RXIE)
|
|
{
|
|
psMsgObject->ui32Flags |= MSG_OBJ_RX_INT_ENABLE;
|
|
}
|
|
|
|
//
|
|
// See if there is new data available.
|
|
//
|
|
if(ui16MsgCtrl & CAN_IF1MCTL_NEWDAT)
|
|
{
|
|
//
|
|
// Get the amount of data needed to be read.
|
|
//
|
|
psMsgObject->ui32MsgLen = (ui16MsgCtrl & CAN_IF1MCTL_DLC_M);
|
|
|
|
//
|
|
// Don't read any data for a remote frame, there is nothing valid in
|
|
// that buffer anyway.
|
|
//
|
|
if((psMsgObject->ui32Flags & MSG_OBJ_REMOTE_FRAME) == 0)
|
|
{
|
|
//
|
|
// Read out the data from the CAN registers.
|
|
//
|
|
_CANDataRegRead(psMsgObject->pui8MsgData,
|
|
(uint32_t *)(ui32Base + CAN_O_IF2DA1),
|
|
psMsgObject->ui32MsgLen);
|
|
}
|
|
|
|
//
|
|
// Now clear out the new data flag.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF2CMSK) = CAN_IF1CMSK_NEWDAT;
|
|
|
|
//
|
|
// Transfer the message object to the message object specified by
|
|
// ui32ObjID.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF2CRQ) = ui32ObjID & CAN_IF1CRQ_MNUM_M;
|
|
|
|
//
|
|
// Wait for busy bit to clear
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF2CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
|
|
//
|
|
// Indicate that there is new data in this message.
|
|
//
|
|
psMsgObject->ui32Flags |= MSG_OBJ_NEW_DATA;
|
|
}
|
|
else
|
|
{
|
|
//
|
|
// Along with the MSG_OBJ_NEW_DATA not being set the amount of data
|
|
// needs to be set to zero if none was available.
|
|
//
|
|
psMsgObject->ui32MsgLen = 0;
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Clears a message object so that it is no longer used.
|
|
//!
|
|
//! \param ui32Base is the base address of the CAN controller.
|
|
//! \param ui32ObjID is the message object number to disable (1-32).
|
|
//!
|
|
//! This function frees the specified message object from use. Once a message
|
|
//! object has been ``cleared,'' it no longer automatically sends or receives
|
|
//! messages, nor does it generate interrupts.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
CANMessageClear(uint32_t ui32Base, uint32_t ui32ObjID)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT(_CANBaseValid(ui32Base));
|
|
ASSERT((ui32ObjID >= 1) && (ui32ObjID <= 32));
|
|
|
|
//
|
|
// Wait for busy bit to clear
|
|
//
|
|
while(HWREG(ui32Base + CAN_O_IF1CRQ) & CAN_IF1CRQ_BUSY)
|
|
{
|
|
}
|
|
|
|
//
|
|
// Clear the message value bit in the arbitration register. This indicates
|
|
// the message is not valid.
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CMSK) = CAN_IF1CMSK_WRNRD | CAN_IF1CMSK_ARB;
|
|
HWREG(ui32Base + CAN_O_IF1ARB1) = 0;
|
|
HWREG(ui32Base + CAN_O_IF1ARB2) = 0;
|
|
|
|
//
|
|
// Initiate programming the message object
|
|
//
|
|
HWREG(ui32Base + CAN_O_IF1CRQ) = ui32ObjID & CAN_IF1CRQ_MNUM_M;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
// Close the Doxygen group.
|
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//! @}
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//
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//*****************************************************************************
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