User's Manual

GE864- QUAD Har dwar e User Guide
1vv0300872 Rev.1 2010-04-02
- All Rights Reserved. Page 41 of 77
Oper ating Range – Inter face Level s (2.8V CMOS)
Level
Min
Max
Input high level V
IH
2.1V
3.3V
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
The table below shows the signals of the GE864 serial port:
RS232 Pin
Num ber
Signal
GE864- QUAD
Pad Num ber
Nam e
Usage
1
DCD
dcd_uar t
D9
Data Carr ier Detect
Output from the GE864-QUAD that indicates the
carrier presence
2
RXD
tx_uar t
H8
Transmit line *
see Note
Output tr ansmit line of GE864-QUAD UART
3
TXD
rx_uart
E7
Receive line * see Note
Input receive of the GE864-QUAD UART
4
DTR
dtr_uar t
B7
Data Ter minal Ready
Input to the GE864-QUAD that contr ols the DTE
READY condition
5
GND
A1,F1,H1,L1, H2,
Ground
gr ound
6
DSR
dsr_uar t
E11
Data Set Ready
Output from the GE864-QUAD that indicates the
module is ready
7
RTS
rts_uart
F7
Request to Send
Input to the GE864-QUAD that contr ols the
Hardware flow control
8
CTS
cts_uar t
F6
Clear to Send
Output from the GE864-QUAD that contr ols the
Hardware flow control
9
RI
ri_uar t
B6
Ring Indicator
Output from the GE864-QUAD that indicates the
incoming call condition
* NOTE:
According to V.24, RX/TX signal names are refer r ed to the application side, therefore
on the GE864 side these signal are on the opposite direction: TXD on the application
side will be connected to the receive line (her e named TXD/ rx_uart ) of the GE864
ser ial port and vice versa for RX.
TIP:
For a minimum implementation, only the TXD and RXD lines can be connected, the
other lines can be left open provided a software flow control is implemented.
TIP:
In order to avoid noise or interferences on the RXD lines it is suggested to add a pull
up resistor (100K Ω to 2.8V)