//------------------------------------------------------------------------------
UINT32 timestamp_calcTimeDiff(tTimestamp* pTimeStampPrevious_p,
tTimestamp* pTimeStampCurrent_p)
{
UINT32 timeDiffTicks;
timeDiffTicks = pTimeStampCurrent_p->timeStamp - pTimeStampPrevious_p->timeStamp;
return OMETH_TICKS_2_NS(timeDiffTicks);
}
DWORD PUBLIC EplTgtTimeStampTimeDiffNs (tEplTgtTimeStamp* pTimeStampPredecessor_p,
tEplTgtTimeStamp* pTimeStampSuccessor_p)
{
DWORD dwTimeDiffTicks;
dwTimeDiffTicks = pTimeStampSuccessor_p->m_dwTimeStamp
- pTimeStampPredecessor_p->m_dwTimeStamp;
return OMETH_TICKS_2_NS(dwTimeDiffTicks);
}
static tEplKernel EdrvCyclicProcessTxBufferList(void)
{
tEplKernel Ret = kEplSuccessful;
tEdrvTxBuffer* pTxBuffer = NULL;
DWORD udwAbsTime; //absolute time accumulator
BOOL fFirstPkt = TRUE; //flag to identify first packet
DWORD udwMacTimeEntry = EDRV_GET_MAC_TIME(); //MAC TIME AT FUNCTION CALL
//DWORD udwMacTimePlusOffset = udwMacTimeEntry + EdrvCyclicInstance_l.m_dwTxProcDur; //plus offset
DWORD udwCycleMin = 0; //absolute minimum cycle time
DWORD udwCycleMax = 0; //absolute maximum cycle time
DWORD udwNextOffNs = 0; //next earliest tx time
DWORD udwNextTimerIrqNs = EdrvCyclicInstance_l.m_dwCycleLenUs * 1000UL; //time of next timer irq
if( EdrvCyclicInstance_l.m_fNextCycleValid == FALSE )
{
//use current time + negative shift to set a valid next cycle
EdrvCyclicInstance_l.m_dwNextCycleTime = udwMacTimeEntry + OMETH_US_2_TICKS(EDRVCYC_NEG_SHIFT_US);
//next timer IRQ correction
udwNextTimerIrqNs -= OMETH_TICKS_2_NS(EdrvCyclicInstance_l.m_dwTxProcDur);
EdrvCyclicInstance_l.m_fNextCycleValid = TRUE;
}
else
{
//cycle is valid, compensate next timer irq
//calculate time difference of Next SoC - approx. entry of this function
DWORD udwDiff;
DWORD udwDiffNs;
udwDiff = EdrvCyclicInstance_l.m_dwNextCycleTime - udwMacTimeEntry;
if( udwDiff & 0x80000000UL )
{
udwDiff = udwMacTimeEntry - EdrvCyclicInstance_l.m_dwNextCycleTime;
udwDiffNs = OMETH_TICKS_2_NS(udwDiff);
udwNextTimerIrqNs -= (EDRVCYC_NEG_SHIFT_US * 1000UL + udwDiffNs);
Ret = EdrvCyclicCycleTimeViolation(udwNextTimerIrqNs);
goto CycleDone;
}
//substract TX buffer list processing from cycle time
udwNextTimerIrqNs -= OMETH_TICKS_2_NS(EdrvCyclicInstance_l.m_dwTxProcDur);
udwDiffNs = OMETH_TICKS_2_NS(udwDiff);
if( udwDiffNs > (EDRVCYC_NEG_SHIFT_US * 1000UL) )
{
//time difference is larger negative shift
udwNextTimerIrqNs += (udwDiffNs - EDRVCYC_NEG_SHIFT_US * 1000UL);
}
else if( udwDiffNs > (EDRVCYC_MIN_SHIFT_US * 1000UL) )
{
//time difference is shorter than negative shift but larger than minimum
udwNextTimerIrqNs -= (EDRVCYC_NEG_SHIFT_US * 1000UL - udwDiffNs);
}
else
{
//time difference is too short => cycle violation!
udwNextTimerIrqNs -= (EDRVCYC_NEG_SHIFT_US * 1000UL - udwDiffNs);
Ret = EdrvCyclicCycleTimeViolation(udwNextTimerIrqNs);
goto CycleDone;
}
}
//set accumulator for cycle window calculation
udwAbsTime = EdrvCyclicInstance_l.m_dwNextCycleTime; //get cycle start time
//set limits to verify if time triggered tx is within cycle
// note: otherwise openMAC would be confused
udwCycleMin = EdrvCyclicInstance_l.m_dwNextCycleTime; //minimum limit
udwCycleMax = EdrvCyclicInstance_l.m_dwNextCycleTime + \
OMETH_US_2_TICKS(EdrvCyclicInstance_l.m_dwCycleLenUs); //maximum limit
//loop through TX buffer list
while ((pTxBuffer = EdrvCyclicInstance_l.m_paTxBufferList[EdrvCyclicInstance_l.m_uiCurTxBufferEntry]) != NULL)
{
//compare TX buffer time offset with next offset (considers IPG and last packet length)
//note: otherwise openMAC is confused if time-trig TX starts within other time-trig TX!
if( (fFirstPkt == FALSE) && (udwNextOffNs > pTxBuffer->m_dwTimeOffsetNs) )
{
udwAbsTime += OMETH_NS_2_TICKS(udwNextOffNs); //accumulate offset
}
else
{
udwAbsTime += OMETH_NS_2_TICKS(pTxBuffer->m_dwTimeOffsetNs); //accumulate offset
}
fFirstPkt = FALSE; //first packet is surely out...
//verify if packet TX start time is within cycle window
if( (udwAbsTime - udwCycleMin) > (udwCycleMax - udwCycleMin) )
{
//packet is outside of the window
Ret = EdrvCyclicCycleTimeViolation(udwNextTimerIrqNs);
goto CycleDone;
}
//pTxBuffer->m_dwTimeOffsetNs = udwAbsTime | 1; //lowest bit enables time triggered send
//set the absolute TX start time, and OR the lowest bit to give Edrv a hint
pTxBuffer->m_dwTimeOffsetAbsTk = udwAbsTime | 1; //lowest bit enables time triggered send
Ret = EdrvSendTxMsg(pTxBuffer);
if (Ret != kEplSuccessful)
{
goto Exit;
}
//set the absolute TX start time to zero
// -> If the TX buffer is reused as manual TX, EdrvSendTxMsg is not confused!
pTxBuffer->m_dwTimeOffsetAbsTk = 0;
//calculate the length of the sent packet, add IPG and thus know the next earliest TX time
{
DWORD udwLength = pTxBuffer->m_uiTxMsgLen;
//consider padding!
if( udwLength < 60UL )
{
udwLength = 60UL;
}
// ( pre + header + payload + padding + crc ) * 80ns/byte + 960ns = next TX time
udwNextOffNs = EDRVCYC_BYTETIME_NS * (EDRVCYC_PREAMB_SIZE + ETH_CRC_SIZE + udwLength) + EDRVCYC_IPG_NS;
}
//switch to next TX buffer
EdrvCyclicInstance_l.m_uiCurTxBufferEntry++;
}
//set up next timer interrupt
Ret = EplTimerHighReskModifyTimerNs(&EdrvCyclicInstance_l.m_TimerHdlCycle,
udwNextTimerIrqNs,
EdrvCyclicCbTimerCycle,
0L,
FALSE);
if (Ret != kEplSuccessful)
{
PRINTF("%s: EplTimerHighReskModifyTimerNs ret=0x%X\n", __func__, Ret);
goto Exit;
}
CycleDone:
//calculate next cycle
EdrvCyclicInstance_l.m_dwNextCycleTime += OMETH_US_2_TICKS(EdrvCyclicInstance_l.m_dwCycleLenUs);
Exit:
return Ret;
}
