LTP5901-WHM/LTP5902-WHM
25
59012whmfa
For more information www.linear.com/LTP5901-WHM or www.linear.com/LTP5902-WHM
OPERATION
reducing system power consumption by allowing the CPU
to remain inactive during the majority of the radio activity.
The Autonomous MAC, provides software-independent
timing control of the radio and radio-related functions,
resulting in superior reliability and exceptionally low power.
SECURITY
Network security is an often overlooked component of a
complete network solution. Proper implementation of se-
curity protocols is significant in terms of both engineering
effort and market value in an OEM product. Eterna system
solutions provide a FIPS-197 validated encryption scheme
that includes authentication and encryption at the MAC
and network layers with separate keys for each mote.
This not only yields end-to-end security, but if a mote is
somehow compromised, communication from other motes
is still secure. A mechanism for secure key exchange al-
lows keys to be kept fresh. To prevent physical attacks,
Eterna includes hardware support for electronically locking
devices, thereby preventing access to Eterna’s flash and
RAM memory and thus the keys and code stored therein.
TEMPERATURE SENSOR
Eterna includes a calibrated temperature sensor on chip.
The temperature readings are available locally through
Eterna’s serial API, in addition to being available via the
network manager. The performance characteristics of
the temperature sensor can be found in the Temperature
Sensor Characteristics section.
RADIO INHIBIT
The RADIO_INHIBIT input enables an external controller
to temporarily disable the radio software drivers (for
example, to take a sensor reading that is susceptible to
radio interference). When RADIO_INHIBIT is asserted
the software radio drivers will disallow radio operations
including clear channel assessment, packet transmits,
or packet receipts. If the radio is active in the current
timeslot when RADIO_INHIBIT is asserted the radio will be
diabled after the present operation completes. For details
on the timing associated with RADIO_INHIBIT, see the
RADIO_INHIBIT AC Characteristics section.
SOFTWARE INSTALLATION
Devices are supplied with the flash erased, requiring pro-
gramming as part of the OEMs manufacturing procedure.
The US Department of Commerce places restrictions on
export of systems and software supporting encryption.
All of Linear/Dust product software produced to date
contains encryption and is subject to export regulations
and may be provided only via MyLinear, https://www.
linear.com/mylinear. Customers purchasing SmartMesh
products will receive a certificate containing a registration
key and registration instructions with their order. After
registering with the key, customers will be able to
download SmartMesh software images from MyLinear.
Once registered, customers will receive automated e-mail
notifications as software updates are made available.
Linear Technology offers the DC9010, in circuit program-
mer for the Eterna based products. While the DC9010, is
provided as a finished product, the design documents are
provided as a reference for customers.
Once software has been loaded, devices can be configured
via either the CLI or API ports. Configuration commands
and settings are defined in SmartMesh WirelessHART Mote
API Guide and SmartMesh WirelessHART Mote CLI Guide.
FLASH DATA RETENTION
Eterna contains internal flash (Non-Volatile Memory) to
store calibration results, unique ID, configuration settings
and software images. Flash retention over the operating
temperature range. See Electrical Characteristics and
Absolute Maximum Ratings sections.
Non destructive storage above the operating temperature
range of –40°C to 85°C is possible; although, this may
result in a degradation of retention characteristics.
The degradation in flash retention for temperatures >85°C
can be approximated by calculating the dimensionless
acceleration factor using the following equation:
Ea
k
•1
T
USE+273 −1
TSTRESS+273