DP83640: PTP_TDR register information

I am trying to find certain information in datasheet for PTP_TDR (page 4), but with no luck.

I am using the dp83640 April 2015 datasheet.

In paragraph  5.6.1.5.2 it is indicated:

"On Writes, successively stores the 16-bit values of Clock time or Trigger Control
Information as selected by controls in the PTP Control Register."

However, I can't find anywhere information about which are the successive stores from Clock time or Trigger Control.

Related to that, in the software development guide I see:

EXPORT void
    PTPArmTrigger (
        IN PEPL_PORT_HANDLE portHandle,
        IN NS_UINT trigger,
        IN NS_UINT32 expireTimeSeconds,
        IN NS_UINT32 expireTimeNanoSeconds,
        IN NS_BOOL initialStateFlag,
        IN NS_BOOL waitForRolloverFlag,
        IN NS_UINT32 pulseWidth,
        IN NS_UINT32 pulseWidth2)

//  Establishes a trigger's expiration time and trigger pulse width behavior.
//  
//  portHandle
//      Handle that represents a port. This is obtained using the EPLEnumPort 
//      function.
//  trigger
//      The trigger to arm, 0 - 7.
//  expireTimeSeconds
//      The seconds portion of the desired expiration time relative to the 
//      IEEE 1588 hardware clock. 
//  expireTimeNanoSeconds
//      The nanoseconds portion of the desired expiration time relative to 
//      the IEEE 1588 hardware clock. This value may be not be larger then 
//      1e9 (1 second).
//  initialStateFlag
//      Indicates initial state of signal to be set when trigger is armed 
//      (FALSE will cause a signal rise at trigger time, TRUE will cause a 
//      signal fall at trigger time). This parameter is ignored in toggle 
//      mode.
//  waitForRolloverFlag
//      If set to TRUE the device should not arm the trigger until after 
//      the seconds field of the clock time has rolled over from 
//      0xFFFF_FFFF to 0.
//  pulseWidth
//      Sets the 50% duty cycle time for triggers 2 - 7. Its format is 
//      bits [31:30] = seconds, [29:0] = nanoseconds. For triggers 0 and 1 
//      sets the width of the first part of the pulse, the width of the 
//      second part of the pulse is set by the pulseWidth2 parameter.
//  pulseWidth2
//      Ignored for triggers 2 - 7. For Triggers 0 and 1, in a single or 
//      periodic pulse type signal, a second pulse width value controls the 
//      2nd pulse width (period is pulseWidth + pulseWidth2). 
//      Its format is bits [31:30] = seconds, [29:0] = nanoseconds.
//
//      For Edge type signals, pulseWidth2 is interpreted as a 16-bit seconds 
//      field and pulseWidth is a 30-bit nanoseconds field. 
//
//  Returns
//      Nothing
//
//  Once this function has been called, the trigger will be armed. 
//****************************************************************************
{
NS_UINT reg;

    OAIBeginMultiCriticalSection( portHandle->oaiDevHandle);
    reg = (trigger << P640_TRIG_SEL_SHIFT) | P640_TRIG_LOAD;
    EPLWriteReg( portHandle, PHY_PG4_PTP_CTL, reg);
    
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, expireTimeNanoSeconds & 0xFFFF);
    
    reg = (expireTimeNanoSeconds >> 16) | (initialStateFlag ? 0x80000000 : 0) |
          (waitForRolloverFlag ? 0x40000000 : 0);
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, reg);
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, expireTimeSeconds & 0xFFFF);
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, expireTimeSeconds >> 16);
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, pulseWidth & 0xFFFF);
    EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, pulseWidth >> 16);
    
    if ( trigger <= 1)
    {
        EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, pulseWidth2 & 0xFFFF);
        EPLWriteReg( portHandle, PHY_PG4_PTP_TDR, pulseWidth2 >> 16);
    }
    
    reg = (trigger << P640_TRIG_SEL_SHIFT) | P640_TRIG_EN;
    EPLWriteReg( portHandle, PHY_PG4_PTP_CTL, reg);
    OAIEndMultiCriticalSection( portHandle->oaiDevHandle);
    return;
}

I can't find in the datasheet these consecutive data fields that are written in PTP_TDR.

Moreover, the above PTPArmTrigger method has a variable name expireTimeSeconds. However, in the example of the software development guide this variable is named ppsStartTime.

        PTPArmTrigger( portHandle, 0, ptpStackCfg->ppsStartTime, 0, 
                       ptpStackCfg->ppsRiseOrFallFlag, FALSE, 500000000, 500000000);

Which of the two holds? Is it a start time or expiring time?