USGlobalsat EB-5635RE - Manual (Page 8)

OPERATING Description
NC
EB-5365RE reserves pin, Just NC.
TIMEMARK
This pin provides one pulse-per-second
output from the board, which is synchronized
to GPS time. This is not available in Trickle
Power mode. If do not use it, Just NC.
GPIO
User can use this I/O pin for special functions.
(For example, control LED)
Wake Up
System power controller, when EB-5365RE
Power ON, this pin will output 1.8V
dc
.
ON_OFF
The ON_OFF pin commands the EB-5365RE
ON or OFF. There are multiple methods of
connecting this pin for different applications
in order to minimize host resource
requirements.
The ON_OFF pin is used to command the
EB-5365RE to turn on or off:
 The turn on command is a hardware
feature of the Power Control FSM based
on sensing a rising edge on the pin.
 The turn off command is a software
feature based on interrupts related to
rising and/or falling edges and/ or
sensing of pin levels. (Not currently
supported.)
The ON_OFF pin processing is carried out by
the Power Control FSM. The ON_OFF rising
edge event during low power modes is
recorded in a status register that is
subsequently read by the processor once it is
running. When the processor is running at
the time of an ON_OFF event, the processor
can poll the status or set-up an interrupt.
VCC_RF
VCC_RF can supply Active Antenna Bias
voltage (3.3V). This pin will supply Active
Antenna. If do not use it, Just NC.
GND
This is Ground pin for the baseband circuit.
RF_IN
This pin receives signal of GPS analog via
external active antenna. It has to be a
controlled impedance trace at 50ohm. Do not
have RF traces closed the other signal path
and routing it on the top layer. Keep the RF
traces as short as possible.
DR I2C Interface
The I²C host port interface supports:
Operation up to 400kbps
Individual transmit and receive FIFO lengths of
64B
■ The default I
2
C address values are:
Rx: 0x60
Tx: 0x62
Multi-master I²C mode is supported by default.
Dead reckoning applications support the DR
I²C interface. The I²C interface supports
required sensor instruments such as gyros,
accelerometers, compasses or other sensors
that can operate with an I²C bus.
DR I²C interface supports:
Typical data lengths (command + in/data out)
of several bytes
Standard I²C bus maximum data rate 400kbps
Minimum data rate 100kbps