LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 55 of 125
1.9.2
DDC (I
2
C) interface
1.9.2.1
Overview
An I
2
C compatible Display Data Channel (DDC) interface for communication with u-blox GPS receivers is available
on LEON-G100 / LEON-G200 modules. This interface is intended exclusively to access u-blox GPS receivers.
Name
Description
Remarks
SCL
I
2
C bus clock line
Fixed open drain. External pull-up required.
SDA
I
2
C bus data line
Fixed open drain. External pull-up required.
Table 18: DDC (I
2
C) pins
DDC (I
2
C) interface pins ESD sensitivity rating is 1 kV (HBM JESD22-A114F). 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 if they are externally accessible on the application board.
u-blox has implemented special features in LEON-G100 / LEON-G200 modules to ease the design effort required
to integrate a u-blox wireless module with a u blox GPS receiver.
Combining a LEON-G100 / LEON-G200 wireless module with a u-blox GPS receiver allows designers full access
to the GPS receiver directly via the wireless module: it relays control messages to the GPS receiver via a dedicated
DDC (I
2
C) interface. A 2
nd
interface connected to the GPS receiver isn’t necessary: AT commands via the UART
serial interface of the wireless module allow full control of the GPS receiver from any host processor.
LEON-G100 / LEON-G200 modules feature embedded u-blox GPS aiding functionalities for enhanced GPS
performance. These provide decreased Time To First Fix (TTFF) and allow faster position calculation with higher
accuracy.
For more details regarding the handling of the DDC (I
2
C) interface and the GPS aiding features refer to
u-blox AT Commands Manual
[2] (AT+UGPS, AT+UGPRF, AT+UGPIOC commands) and
GPS
Implementation Application Note
