Sierra Wireless AIRPRIME WISMO218 - Manual (Page 74)

WA_DEV_W218_PTS_002 Rev 006 April 29, 2010 74
Product Technical Specification &
Customer Design Guidelines Interfaces
3.18. Reset
The AirPrime WISMO218 has an input ~RESET pin. This is a hardware reset and should only be
used for emergency reset. The ~RESET pin should be kept at low level for at least 500µs to
guarantee a proper reset to take place.
3.18.1. Feature
The ~RESET signal has a 100K  internal pull up resistor to VCC_2V8.
Figure 38. Reset Timing
Table 36: Electrical Characteristics of the Signals
Parameter Minimum Typ Maximum Unit
~RESET
Input Impedance ( R )* - 100K - 
Input Impedance (C) - 10nF F
Cancellation time (Ta)
at power up only
- 38 - ms
V
H
** 1.57 - - V
V
IL
- 0 1.2 V
V
IH
1.96 2.8 -- V
* Internal pull up resistance
** V
H :
Hysterisis Voltage
3.18.1.1. Sequence After an External Reset Event (~RESET)
To activate the « emergency » reset sequence, the ~RESET signal has to be set to LOW level
manually, for example, by a push button.
3.18.2. Pin Description
Table 37: Reset Pin Descriptions
Signal Pin Number I/O I/O Type Description
~RESET 12 100K Pull-up 2V8
AirPrime WISMO218
Reset