User's Manual

GE864
GE864GE864
GE864-
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-QUAD Automotive V2 Hardware User Guide
QUAD Automotive V2 Hardware User GuideQUAD Automotive V2 Hardware User Guide
QUAD Automotive V2 Hardware User Guide
1vv0300840 Rev.3 2010-04-08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 36 of 71
9. Serial Ports
The serial port on the Telit GE864-QUAD Automotive V2 is the core of the interface
between the module and OEM hardware.
2 serial ports are available on the module:
• MODEM SERIAL PORT
• MODEM SERIAL PORT 2 (DEBUG)
9.1.
9.1.9.1.
9.1. MODEM SERIAL PORT
MODEM SERIAL PORTMODEM SERIAL PORT
MODEM SERIAL PORT
Several configurations can be designed for the serial port on the OEM hardware, but
the most common are:
• RS232 PC com port
• microcontroller UART @ 2.8V - 3V (Universal Asynchronous Receive Transmit)
• microcontroller UART@ 5V or other voltages different from 2.8V
Depending from the type of serial port on the OEM hardware a level translator circuit
may be needed to make the system work. The only configuration that doesn't need a
level translation is the 2.8V UART.
The serial port on the GE864-QUAD Automotive V2 is a +2.8V UART with all the 7 RS232
signals. It differs from the PC-RS232 in the signal polarity (RS232 is reversed) and
levels. The levels for the GE864-QUAD Automotive V2 UART are the CMOS levels:
Absolute Maximum Ratings
Absolute Maximum Ratings Absolute Maximum Ratings
Absolute Maximum Ratings -
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-Not Functional
Not FunctionalNot Functional
Not Functional
Parameter
ParameterParameter
Parameter Min
MinMin
Min Max
MaxMax
Max
Input level on any
digital pad when on
-0.3V +3.1V
Input voltage on
analog pads when on
-0.3V +3.0 V
Operating Range
Operating Range Operating Range
Operating Range -
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- Interface levels (2.8V CMOS)
Interface levels (2.8V CMOS) Interface levels (2.8V CMOS)
Interface levels (2.8V CMOS)
Level
LevelLevel
Level Min
MinMin
Min Max
MaxMax
Max
Input high level V
IH
2.1V 3.1V
Input low level V
IL
0V 0.5V
Output high level V
OH
2.2V 3.0V
Output low level V
OL
0V 0.35V