Data Sheet

ZOE-M8 - Data Sheet
UBX-16008094 - R07 Production Information Functional description
Page 11 of 29
The receiver combines a number of checks on the received signals looking for inconsistencies across several
parameters.
This feature does not guarantee to detect all spoofing attacks.
1.14 EXTINT: External interrupt
EXTINT is an external interrupt pin with fixed input voltage thresholds with respect to VCC. It can be used for
control of the receiver or for aiding.
For more information about how to implement and configure these features, see the u-blox 8 / u-blox M8 Receiver
Description including Protocol Specification [2] and the ZOE-M8 Hardware Integration Manual [1].
1.14.1 Pin control
The pin control feature allows overriding the automatic active/inactive cycle of power save mode. The state of the
receiver can be controlled through the EXTINT pin.
The receiver can also be forced OFF using EXTINT when power save mode is not active.
1.14.2 Aiding
The EXTINT pin can be used to supply time or frequency aiding data to the receiver.
For time aiding, the time can be supplied using hardware time synchronization where an accurate time pulse is
connected to the EXTINT pin.
Frequency aiding can be implemented by connecting a periodic rectangular signal with a frequency up to 500 kHz
and arbitrary duty cycle (low/high phase duration must not be shorter than 50 ns) to the EXTINT pin, and providing
the applied frequency value to the receiver using UBX messages.
1.15 TIMEPULSE
A configurable time pulse signal is available with u-blox ZOE-M8 SiPs.
The TIMEPULSE output generates pulse trains synchronized with GPS or UTC time grid with intervals configurable
over a wide frequency range. Thus it may be used as a low frequency time synchronization pulse or as a high
frequency reference signal.
By default the time pulse signal is configured to 1 pulse per second. For more information see the u-blox 8 / u-blox
M8 Receiver Description including Protocol Specification [2].
1.16 Protocols and interfaces
Protocol Type
NMEA Input/output, ASCII, 0183, version 4.0 (configurable to V2.1, V2.3 or V4.1)
UBX Input/output, binary, u-blox proprietary
RTCM Input, messages 1, 2, 3, 9
Table 4: Available Protocols
All protocols are available on UART, DDC (I
2
C compliant) and SPI. For the specifications of the various protocols,
see the u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [2].
1.17 Interfaces
A number of interfaces are provided either for data communication or memory access. The embedded firmware
uses these interfaces according to their respective protocol specifications.
1.17.1 UART