User's Guide

UL865 Hardware User Guide
1VV0301050 Rev 2 – 2013-10-09
The signals of the UL865 serial port are:
RS232 Pin
Number
Signal
UL865
Pad Number
Name
Usage
1
DCD - dcd_uart
1
Data Carrier Detect
Output from the UL865 that indicates the
carrier presence
2
RXD - tx_uart
8
Transmit line *see Note
Output transmit line of UL865 UART
3
TXD - rx_uart
7
Receive line *see Note
Input receive of the UL865 UART
4
DTR - dtr_uart
4
Data Terminal Ready
Input to the UL865 that controls the DTE
READY condition
5
GND
32, 33, 35, 36, 46
Ground
Ground
6
DSR - dsr_uart
3
Data Set Ready
Output from the UL865 that indicates the
module is ready
7
RTS -rts_uart
5
Request to Send
Input to the UL865 that controls the
Hardware flow control
8
CTS - cts_uart
6
Clear to Send
Output from the UL865 that controls the
Hardware flow control
9
RI - ri_uart
2
Ring Indicator
Output from the UL865 that indicates the
incoming call condition
The following table shows the typical input value of internal pull-up resistors for RTS DTR
and TXD input lines and in all module states:
STATE
RTS DTR TXD
Pull up tied to
ON
5K to 12K
1V8
OFF
Schottky diode
RESET
Schottky diode
POWER
SAVING
5K to 12K
1V8
The input line ON_OFF and RESET state can be treated as in picture below