3 9
P r o g r a m m i n g C o n s i d e r a t i o n s
Soft Reset
Net+OS provides an internal facility to enact a soft reset, but it is the responsibility of a
specific implementation to choose a reasonable trigger to invoke it. One choice is to use a
GPIO pin as a signal to trigger a soft reset. The Digi Connect ME has one GPIO pin named
"/INIT” (PORTC5) that is not normally assigned to any other task. It is an ideal candidate
for a soft reset. The signal is exposed via pin 20 on the 20-pin header, so it can be
controlled by an embedded host. When plugged into the development board, the /INIT
signal is pulled high, unless a jumper is placed across pins 2 and 3 of jumper block P12. In
this way, placing the jumper simulates pressing a soft reset button.
The naresetapp example application demonstrates a simple mechanism for monitoring a
GPIO pin and then initiating a soft reset when the pin achieves a particular value.
Reset Characteristics
Characteristic
Specification
Delay
200 milliseconds (typical)
Threshold
2.88 V
Minimum Hold Time
1 microsecond pulse
DC_ME-HWR.book Page 39 Thursday, July 1, 2004 11:12 AM
Summary of Contents for Digi Conntect ME
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