User's Manual

DE910 Series Hardware User Guide
1vv0301183 Rev.1 – 2015-2-13
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Reserved. Page 23 of 70
4.2.1. Shutdown by Software Command
The DE921 can be shut down by a software command.
When a shutdown command is sent, the DE921 goes into the finalization state and will shut
down PWRMON at the end of this state.
The period of the finalization state can vary according to the state of the DE921 so it cannot
be fixed definitely.
Normally it will be above 10 seconds after sending a shutdown command and DTE should
monitor the status of PWRMON to see the actual power off.
TIP:
To check if the device has powered off hardware line PWRMON must be monitored. When
PWRMON goes low, the device has powered off.
4.2.2. Hardware Shutdown
To turn OFF the DE921 the pad ON_OFF* must be tied low for at least 2 seconds and then
released. The same circuitry and timing for the power on must be used.
When the hold time of ON_OFF* is above 2 seconds, the DE921 goes into the finalization
state and will shut down PWRMON at the end of this state.
The period of the finalization state can vary according to the state of the DE921 so it cannot
be fixed definitely.
Normally it will be above 10 seconds after releasing ON_OFF* and DTE should monitor the
status of PWRMON to see the actual power off.