Hello, I have the following problem: I implemented a CAN Transmit FIFO containing 11 message objects static allocated to one message list in numerical...
Show More
Hello,
I have the following problem: I implemented a CAN Transmit FIFO containing 11 message objects static allocated to one message list in numerical order. The CAN Fifo is used by the XCP Protocol to transmit a set of DAQ-Messages with each event (every 1000ms, burst of x messages). When I configure the XCP to send a set of 4 messages each 1000ms everything is ok, but when I try to send 5 or more messages each 1000ms it works for about 20-30message and then I get an error (my function detects TXRQ not reset and returns FUNC_RETURN_ERROR). When I check the registers with the debugger all TXRQ bits of the message Objects are set but no message Object has the TXEN1 bit set (which should be done by Hardware after submitting the message of the previous object in the FIFO).
To update the Content of the FIFO my software uses the SEL-pointer within the MOFGPR-register of the FIFO base object (the SEL pointer is pointing to the next message object in the FIFO where the Software can put new data in). Before updating the Message object pointed to by the SEL of the base object I clear the MSGVAL bit. After setting up the new frame data I set the NEWDAT bit, reset the RTSEL bit and set the MSGVAL bit again. After that I set the TXRQ bit to enable the object for transmission when the CUR pointer of the base object is set to this object and the Hardware sets the TXEN1 bit.
Is it a problem when MSGVAL bit is reset when the Hardware moves the CUR pointer to this object and tries to set the TXEN1-Bit? Or is the problem the reset of the RTSEL bit after configuring the message object? I havent found anything for this topic within the user manual...
I paste the code of the transmit function down below. The parameter objIdx is the Index of the FIFO base object.
/**
* @brief Update data and length of TX message object and set Transmit Request for selected message
* @note -
* @param[in] objIdx Index of the HW message object (0..63 for a XMC4500)
* @param[in] length Number of data bytes the message object contains (0..8)
* @param[in] data Pointer to data array
* @retval Status of operation: FUNC_RETURN_OK if data in message object is updated, else FUNC_RETURN_ERROR
*/
sint32_t MCAN0_UpdateMsgObjTxDataAndTransmit(uint8_t objIdx, uint8_t length, const uint8_t * data)
{
sint32_t status = FUNC_RETURN_OK;
uint32_t objIdx_intern = objIdx;
CAN_MO_TypeDef * msgObj = (CAN_MO_TypeDef *)CAN_MO0_BASE;
// *** Check parameter ***
// Check objIdx
if ( objIdx_intern >= MCAN0_MSG_OBJ_CNT )
{
status = FUNC_RETURN_ERROR;
}
else if ( length > 8 )
{
status = FUNC_RETURN_ERROR;
}
else
{ // Parameter ok..
if ( (msgObj[objIdx_intern].MOSTAT & CAN_MO_MOSTAT_DIR_Msk) != 0 )
{
// DIR Bit in MOSTAT is set -> transmit message object
if ( (msgObj[objIdx_intern].MOFCR & CAN_MO_MOFCR_MMC_Msk) != 0 )
{
// Fifo or Gateway Source...
if ( (msgObj[objIdx_intern].MOFCR & CAN_MO_MOFCR_MMC_Msk) == (((uint32_t)2< {
// Transmit Fifo Base Object
uint32_t next, sel, top, bot;
sel = (msgObj[objIdx_intern].MOFGPR & CAN_MO_MOFGPR_SEL_Msk) >> CAN_MO_MOFGPR_SEL_Pos;
top = (msgObj[objIdx_intern].MOFGPR & CAN_MO_MOFGPR_TOP_Msk) >> CAN_MO_MOFGPR_TOP_Pos;
bot = (msgObj[objIdx_intern].MOFGPR & CAN_MO_MOFGPR_BOT_Msk) >> CAN_MO_MOFGPR_BOT_Pos;
if ( sel == top )
{
next = bot;
}
else
{
next = sel+1U; // TODO: msg-objects could be out of order in case of dynamic list linking!
}
if ( (msgObj[sel].MOSTAT & CAN_MO_MOSTAT_TXRQ_Msk) != 0 )
{
// Message object is busy TODO
status = FUNC_RETURN_ERROR;
}
else
{
uint8_t i;
uint32_t tmp;
msgObj[objIdx_intern].MOFGPR &= ~(uint32_t)CAN_MO_MOFGPR_SEL_Msk;
msgObj[objIdx_intern].MOFGPR |= (uint32_t)(((uint32_t)next<
objIdx_intern = sel;
// Reset Message Object valid bit
msgObj[objIdx_intern].MOCTR = CAN_MO_MOCTR_RESMSGVAL_Msk;
// Configure data length
tmp = msgObj[objIdx_intern].MOFCR & ~CAN_MO_MOFCR_DLC_Msk; // clear old settings
msgObj[objIdx_intern].MOFCR = tmp | (((uint32_t)length << CAN_MO_MOFCR_DLC_Pos) & CAN_MO_MOFCR_DLC_Msk);
// Configure Data registers
for ( i = 0U; i < length; i++ )
{
if (i < 4U)
{
uint32_t pos = (uint32_t)i*8UL;
uint32_t mask = CAN_MO_MODATAL_DB0_Msk << ((uint32_t)i*8UL);
uint8_t dataByte = data;
msgObj[objIdx_intern].MODATAL = msgObj[objIdx_intern].MODATAL & ~mask; // delete old byte
msgObj[objIdx_intern].MODATAL |= ((uint32_t)dataByte << pos) & mask;
}
else
{
uint32_t pos = ((uint32_t)i-4UL)*8UL;
uint32_t mask = CAN_MO_MODATAL_DB0_Msk << (((uint32_t)i-4UL)*8UL);
uint8_t dataByte = data;
msgObj[objIdx_intern].MODATAH = msgObj[objIdx_intern].MODATAH & ~mask; // delete old byte
msgObj[objIdx_intern].MODATAH |= ((uint32_t)dataByte << pos) & mask;
} // if(i < 4)
} // for ( i = 0U; i < length; i++ )
// Set NEWDAT bit
msgObj[objIdx_intern].MOCTR = CAN_MO_MOCTR_SETNEWDAT_Msk;
// Reset RTSEL and Set MSGVAL bits
msgObj[objIdx_intern].MOCTR = (CAN_MO_MOCTR_RESRTSEL_Msk |
CAN_MO_MOCTR_SETMSGVAL_Msk );
if( (msgObj[objIdx_intern].MOSTAT & CAN_MO_MOSTAT_TXRQ_Msk) != 0U )
{
status = FUNC_RETURN_ERROR;
}
else
{
// set TXRQ bit
msgObj[objIdx_intern].MOCTR = CAN_MO_MOCTR_SETTXRQ_Msk;
}
} // if ( (msgObj[objIdx_intern].MOSTAT & CAN_MO_MOSTAT_TXRQ_Msk) != 0 ) ... else
}
else
{
// not supported...
status = FUNC_RETURN_ERROR;
}
}
} // if ( (msgObj[objIdx_intern].MOSTAT & CAN_MO_MOSTAT_DIR_Msk) != 0 )
else
{
// selected an RX Message Object for TX operation
status = FUNC_RETURN_ERROR;
}
}
return status;
} // sint32_t MCAN0_UpdateMsgObjTxDataAndTransmit(uint8_t objIdx, uint8_t length, const uint8_t * data)
Show Less
Oct 23, 2015
