Integration Guide
Version 1.11
GSM0000PB001
Page 33
1.11 - 4/22/03
6.7.5
General Purpose Input/Output Interface (GPIO)
Eight general-purpose signals (GPIO1-8) are provided. Each of these signals may be selected as inputs or
outputs. They may be used independently as a user-specified function, or may be used to provide modem
control and status signals. Several examples of modem control signals are: power shutdown command,
register/deregister on network command, and transmitter disable. Several examples of modem status
signals are: registration status and ready-for-power-down status to be used with power shutdown command
signal.
I/O Lines
Parameter/Conditions
MIN TYP MAX UNIT
V
IL
Input Voltage – Low
-0.5 0.9 Vdc
V
IH
Input Voltage – High
2.0 3.4 Vdc
V
OL
Output Voltage – Low
0.64 Vdc
V
OH
Output Voltage – High
2.4 3.0 Vdc
I
IL
/ I
IH
Input Leakage Current
-1 1
µµµµ
A
I
OL
/ I
OH
Rated Output Current
2 mA
6.7.6 Analog-To-Digital
Input
Analog-To-Digital Input
Parameter/Conditions
MIN TYP MAX UNIT
ADC
BRES
ADC Binary Resolution
10 Bits
ADC
REF
ADC Reference Voltage
1.75 Vdc
V
ADC
ADC Range
0 1.75 Vdc
Z
ADC
ADC Input Impedance
100 k
Ω
Ω
Ω
Ω
6.7.7 Digital-To-Analog
Output
Digital-To-Analog Output
Parameter/Conditions
MIN TYP MAX UNIT
DAC
BRES
DAC Binary Resolution
10 Bits
T
S
Settling Time
10
µµµµ
S
V
OMAX
Output Voltage with Code
Maximum
2.0 2.2 2.4 Vdc
V
OMIN
Output Voltage with Code
Minimum
0.18 0.24 0.3 Vdc
