To initialize a trigger, the trigger configuration can be set using the appropriate PTP Trigger Configuration Register. Arming a trigger consists of the following steps

1. Set the 'Trigger Load' bit in the PTP Control Register (PTP_CTL) along with the 'Trigger Select' setting for the trigger. This disables the trigger if the trigger was previously enabled.
2. Write to PTP_TDR: Start_time_ns[15:0]
3. Write to PTP_TDR: Initial state, Wait for Rollover, Start_time_ns[29:16] (Initial state is the stage of the GPIO before triggering starts) (If wait for rollover bit is set, the bit indicates that the trigger is not be armed until the seconds field of the clock time has rolled over from 0xFFFF_FFFF to 0.)
4. Write to PTP_TDR: Start_time_sec[15:0]
5. Write to PTP_TDR: Start_time_sec[31:16]
6. Write to PTP_TDR: Pulsewidth[15:0]
7. Write to PTP_TDR: Pulsewidth[31:16]
8. Write to PTP_TDR: Pulsewidth2[15:0]
9. Write to PTP_TDR: Pulsewidth2[31:16]
10. Set the 'Trigger Enable' bit in the PTP_CTL register along with the 'Trigger Select' setting for the trigger

For Edge type signals, Pulsewidth2 is interpreted as a 16-bit seconds field and Pulsewidth1 is a 30-bit nanoseconds field.

For Triggers 0 and 1, when used for Single or Periodic Pulse type signal, Pulsewidth controls the first pulse width and Pulsewidth2 value controls the second pulse width (total period is Pulsewidth + Pulsewidth2). For Pulsewidth and Pulsewidth2, bits[31:30] is the seconds field and bits[29:0] is the nanoseconds field.

For all other triggers in periodic mode, the high and low pulse widths are the same (period is twice Pulsewidth) and Pulsewidth2 is not used. For Pulsewidth, bits[31:30] is the seconds field and bits[29:0] is the nanoseconds field.

Step 10 is not necessary if all appropriate fields are written. If fields are not changing from previous settings, the latter writes to the PTP_TDR register can be skipped and step 10 can be excluded.

Reading the trigger control settings is similar to the process for writing these values.

1. Set the 'Trigger Read' bit in the PTP Control Register (PTP_CTL) along with the 'Trigger Select' setting for the trigger.
2. Read fields from PTP_TDR in same order as written above.