Specifications

XT55 Hardware Interface Description
Confidential / Preliminary
s
mo b i l e
XT55_hd_v00.02 Page 63 of 116 17.03.2004
3.12 Control signals
3.12.1 Inputs
Table 17: Input control signals of the GSM/GPRS part of the XT55 module
Signal Pin Pin status Function Remarks
Falling edge Power up XT55
Ignition
GSM_IGT
Left open or HiZ No operation
Active low ³ 100ms (Open
drain/collector driver to GND
required in cellular device
application).
Note: If a charger and a
battery is connected to the
customer application the
GSM_IGT signal must be 1s
minimum.
Low Power down XT55
Emergency
shutdown
GSM_EMERG-
OFF
Left open or HiZ No operation
Active low ³ 3.2s (Open
drain/collector driver
required in cellular device
application). At the
GSM_EMERGOFF signal
the watchdog signal of the
GSM engine can be traced
(see description in Table
27).
(HiZ = high impedance)