Altera cyclone V Technical Reference page 1596

cv_5v4
2016.10.28
Bit Name
Ethernet Media Access Controller
Send Feedback
Description
Programming these bits with a non-
zero value instructs the MAC to
initiate an event. Once the command
is transferred or synchronized to
the PTP clock domain, these bits get
cleared automatically. The Software
should ensure that these bits are
programmed only when they are all-
zero. The following list describes
the values of PPSCMD0:
* 0000: No Command
* 0001: START Single Pulse
This command generates single pulse
rising at the start point defined in
Target Time Registers (register 455
and 456) and of a duration defined
in the PPS0 Width Register.
* 0010: START Pulse Train
This command generates the train of
pulses rising at the start point
defined in the Target Time Registers
and of a duration defined in the
PPS0 Width Register and repeated at
interval defined in the PPS Interval
Register. By default, the PPS pulse
train is free-running unless stopped
by 'STOP Pulse train at time' or
'STOP Pulse Train immediately'
commands.
* 0011: Cancel START
This command cancels the START
Single Pulse and START Pulse Train
commands if the system time has not
crossed the programmed start time.
* 0100: STOP Pulse train at time
This command stops the train of
pulses initiated by the START Pulse
Train command (PPSCMD = 0010) after
the time programmed in the Target
Time registers elapses.
* 0101: STOP Pulse Train immediately
This command immediately stops the
train of pulses initiated by the
START Pulse Train command (PPSCMD =
0010).
* 0110: Cancel STOP Pulse train
This command cancels the STOP pulse
train at time command if the
programmed stop time has not
elapsed. The PPS pulse train becomes
free-running on the successful
17-381
PPS_Control
Access Reset
Altera Corporation