User's Manual

LISA-U1/LISA-H1 series - System Integration Manual
3G.G2-HW-10002-2 Advance Information System description
Page 43 of 116
The signal names of the LISA-U1/LISA-H1 series modules UART interface conform to the ITU-T V.24
Recommendation [3].
UART interfaces include the following lines:
Name
Description
Remarks
DSR
Data set ready
Module output
Circuit 107 (Data set ready) in ITU-T V.24
RI
Ring Indicator
Module output
Circuit 125 (Calling indicator) in ITU-T V.24
DCD
Data carrier detect
Module output
Circuit 109 (Data channel received line signal detector) in ITU-T V.24
DTR
Data terminal ready
Module input
Circuit 108/2 (Data terminal ready) in ITU-T V.24
Internal active pull-up to V_INT (1.8 V) enabled.
RTS
Ready to send
Module hardware flow control input
Circuit 105 (Request to send) in ITU-T V.24
Internal active pull-up to V_INT (1.8 V) enabled.
CTS
Clear to send
Module hardware flow control output
Circuit 106 (Ready for sending) in ITU-T V.24
TxD
Transmitted data
Module data input
Circuit 103 (Transmitted data) in ITU-T V.24
Internal active pull-up to V_INT (1.8 V) enabled.
RxD
Received data
Module data output
Circuit 104 (Received data) in ITU-T V.24
GND
Ground
Table 18: UART interface signals
The UART interface pins ESD rating is 1 kV (contact discharge). A higher protection level could be
required if the lines are externally accessible on the application board. A higher protection level can be
achieved mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor array) on the lines
connected to these pins.
1.9.2.1 UART features
All flow control handshakes are supported by the UART interface and can be set by appropriate AT commands
(see u-blox AT Commands Manual [2], &K, +IFC, \Q AT commands): hardware flow control (RTS/CTS), software
flow control (XON/XOFF), or none flow control.
Hardware flow control is enabled by default.
The following baud rates can be configured using AT commands:
 1200 b/s
 2400 b/s
 4800 b/s
 9600 b/s
 19200 b/s
 38400 b/s