4: Interfaces Specification; Overview; Uart - Sierra Wireless AirPrime BX3100 Hardware Integration Manual

4: Interfaces Specification

4.1 Overview

This section describes the interfaces supported by the AirPrime BX310x embedded
module and provides specific voltage, timing, and circuit recommendations for each
interface.

4.2 UART

The AirPrime BX310x provides one UART interface for asynchronous communication
between the AirPrime BX310x module and a host device (e.g. a PC or host
processor):
•
Note: Up to two additional UART interfaces can be added by configuring GPIOs using AT
commands.
Flow control is managed using:
•
•
Table 4-1 on page 15
Table 4-1: UART0 Pins
Pin Interface
2
3
UART0
4
5
a. If UART0 pins are not used, leave open.
Note: UART signals are named with respect to the HOST, and directions are listed with respect
to the module. For example, UART0_RXD is an output from the module to the host.
The UART interface is configurable via AT commands:
•
•
Rev 3 Sep.18
UART0—4-wire, RS-232-compliant interface
RTS/CTS signals (This method is required for higher UART interface speeds.)
or
Software XON/XOFF
describes the signals used for UART0.
a
Name
UART0_RTS
UART0_CTS
UART0_TXD
UART0_RXD
Default configuration—115200 (baudrate), 8 bit, no parity, no handshaking
Baudrate considerations:
· Maximum supported—5 Mbaud
· Maximum tested—3 Mbaud. This is the maximum baudrate supported by the
BX310x Dev Kit FTDI converter IC.
· HW handshaking is recommended above rates of 1 Mbaud and can be
enabled via AT command (AT&K3).
15
Direction Function
I Ready To Send, flow control
O Clear To Send, flow control
I Transmit Data
O Receive Data
4
Voltage Level
VDD_PADS_BB
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