User's Manual

GC864 Hardware User Guide
1vv0300733 Rev.12 – 2009-06-04
Operating Range – Interface levels (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 GC864-QUAD/PY serial port:
RS232 Pin
Number
Signal GC864-
QUAD / PY
Pad
Number
Name Usage
1
DCD –
dcd_uart
32 Data Carrier Detect
Output from the GC864-QUAD / PY that indicates
the carrier presence
2
RXD –
tx_uart
26 Transmit line *see Note
Output transmit line of GC864-QUAD / PY UART
3
TXD –
rx_uart
25 Receive line *see Note
Input receive of the GC864-QUAD / PY UART
4
DTR –
dtr_uart
29 Data Terminal Ready
Input to the GC864-QUAD / PY that controls the DTE
READY condition
5 GND 5,6,7 Ground ground
6
DSR –
dsr_uart
27 Data Set Ready
Output from the GC864-QUAD / PY that indicates
the module is ready
7
RTS –
rts_uart
31 Request to Send
Input to the GC864-QUAD / PY that controls the
Hardware flow control
8
CTS –
cts_uart
28 Clear to Send
Output from the GC864-QUAD / PY that controls the
Hardware flow control
9 RI – ri_uart 30 Ring Indicator
Output from the GC864-QUAD / PY that indicates
the incoming call condition
*NOTE:
According to V.24, RX/TX signal names are referred to the application side, therefore
on the GC864-QUAD/PY side these signal are on the opposite direction: TXD on the
application side will be connected to the receive line (here named TXD/ rx_uart ) of
the GC864-QUAD/PY serial port and viceversa for RX.
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