SE868-V3 Product User Guide
1VV0301205 r4 – 2016-01-20
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 42 of 76
Mod. 0805 2015-02 Rev.4
9.7.
Host I/O Port Configuration and Operation
The receiver module includes two serial ports which are configured for the desired interface.
The first host port can be configured to communicate using a UART, I2C, or SPI interface.
See
Section 9.7.1 Host Port Configuration for 1st Port
for details of port configuration.
Contact Telit support for implementation of this signal.
The second host port is configured in the firmware build with one of two options:
•
UART for message and command communication
•
I
2
C for MEMS wakeup
Note: SPI is not available because it requires 4 pins
The default is I
2
C for MEMS wakeup.
Please contact Telit support
for details of port configuration.
Also, see
Section 4.14 MEMS Wakeup (2nd Port - I2C).
9.7.1.
Host Port Configuration for 1
st
Port (port 0)
The receiver module includes a full-duplex serial interface which is configured for UART, I2C
or SPI interface by reading GPIO6 and GPIO7 at start-up or reset (only).
The following table gives the required input signals:
Pin
Pullup /
Pulldown
UART
I
2
C
(multi-master)
SPI
(slave)
GPIO6
Weak
internal
pulldown
Pullup
10 k
Ω to +1.8 V
(may become CTS)
Float
Float
(becomes SCLK)
GPIO7
Weak
internal
pullup
Float
(may become RTS)
Pulldown
10 kΩ to ground
Float
(becomes SPI_CS)
Table 9-7 Host I/O Port Configuration – First port (port 0)
Note
: GPIO6 and GPIO7 are read for configuration purposes at power up or reset only.
Afterwards, they may be used for UART or SPI signal lines depending on firmware options.