Sierra Wireless AirPrime SL808 Series, Product Technical Specification & Customer Design Manuallines, Page: 68 / 122

Product Technical Specification & Customer Design Guidelines
68 Proprietary and Confidential - Specifications subject to change 2400058
5.3 Reset Signal (SYSTEM_RESET_N)
This signal is used to force the AirPrime SL808X Embedded Module to reset.
Note that an operating system reset is preferred to a hardware reset.
Caution: This signal should only be used for EMERGENCY resets.
5.3.1 Pin descriptions
Table 5-5 describes the SYSTEM_RESET_N signal pin.
See Digital I/O electrical information on page 39 for1V8 voltage characteristics
and reset state definitions.
5.3.2 Electrical characteristics
Table 5-6 describes the reset signal’s electrical characteristics.
Refer to Table 4-2 on page 34 for basic characteristics (type, voltage).
Table 5-4: Reset signal features
Feature Details
Purpose Reset modem
•
Used by host to reset the modem.
Implementation
•
Digital input. 1.8 V logic
•
Signal is driven only by an open-drain output from the host.
•
Host must provide a 50-100 k

external pull-up resistor to 1.8 V.
Note: This pin is also required for JTAG programming.
Table 5-5: Reset signal pin description
Pin Signal I/O I/O type Description
63
SYSTEM_RESET_N I 1V8 Embedded module
reset
Table 5-6: Reset signal electrical characteristics
Parameter Minimum Typical Maximum Unit
Input impedance (R)
a
100 k

Input impedance (C) 10n F
SYSTEM_RESET_N
time (Rt)
b
200 us