Silicon Laboratories Inc.

Ember Corporation

Dewitt Clinton Seward, Iv

Clayton H Daigle

Gregory A Hodgson

Jonathan Everett Avey

Andrew James Wheeler

Timothy Thomas Rueger

Gang Yuan

Greg Hodgson

Preston Fick

Rasmus Christian Larsen

Clay Daigle

Wing Ming Cheung

Bernt Georg Breivik

Lee Byrd

Positive and negative glitch detectors detect glitches on a supply voltage node. The positive glitch detector has a capacitor and a resistor serially coupled between the supply voltage node and ground. An amplifier is coupled to a first node between the capacitor and resistor. A positive glitch results in the glitch on the first node (normally biased low) and generation of a clock pulse by the amplifier that causes a latch to assert its output to indicate the positive glitch. The negative glitch detector has a capacitor and resistor coupled in parallel between the supply voltage node and a second node. A negative glitch on the supply voltage node decreases the voltage on the second node (normally biased high) and an inverting amplifier coupled to the second node generates a clock pulse to cause a latch to assert its output to indicate the negative voltage glitch.

Voltage glitch detectors

A system and method for determining whether a cryptographic system is being observed for power consumption analysis in an attempt to decipher secret keys. The system comprises a first external connection to receive an input voltage, an internal voltage regulator with an external capacitor to produce the desired voltage for the cryptographic system. The internal voltage regulator typically includes a switch that passes current from the first external connection to the external capacitor. By monitoring the frequency at which the switch is activated, it is possible to detect that an external voltage is being applied to the external capacitor. This external voltage is typically used to perform SPA or DPA operations. Thus, the cryptographic system may cease performing any encryption or decryption operations if an external voltage is detected.

Countermeasure for power injection security attack

A system and method of allowing a new device to join an existing network are disclosed. A configuration tool is used to communicate relevant information from the new network device to the gateway in the existing network using a secondary network protocol different from that used by the primary network. For example, in one embodiment, messages are exchanged between the configuration tool and the new device and between the configuration tool and the gateway using BLUETOOTH&#xae;. Once all of the pertinent information has been exchanged, the new device is able to securely join the primary network, which may be based on the IEEE802.15.4 standard.

Use of a network to commission a second network

A system and method of allowing a network device to receive a customized version of a reference design is disclosed. In one embodiment, many values that may be subject to customization are no longer fixed by the reference design. Rather, the reference design utilizes rewritable non-volatile memory to store a set of customization values that can be changed, based on a customer's preference. The system also includes a configuration tool, which interfaces with the network device. Using vendor-unique commands, the configuration tool is able to initialize this set of customization values to the values requested by the customer. In operation, the reference design is downloaded into the network device. The configuration tool is then used to establish the customized parameters for a particular customer. This process allows the manufacturer to create one reference design, which can be customized without the need to modify the code or recompile the source code.

Over the air image configuration

A system and method for allowing legacy devices to be discovered on a DotDot network is disclosed. The system includes a gateway device to interface between DotDot devices and legacy devices. In some embodiments, the gateway device has a plurality of network interfaces to communicate with these legacy devices. The gateway device discovers the legacy devices that it can communicate with. The gateway device then presents information about these legacy devices in a Resource Directory. In some embodiments, the Resource Directory is maintained within the gateway device. In other embodiments, the gateway device utilizes a Resource Directory that exists on the DotDot network.

Gateway using resource directory

A system and method of allowing a network device to enter RF test mode without changing the software image or attaching cables to it is disclosed. In one embodiment, the software image loaded into the network device has the capability to execute in both normal operating mode and RF test mode. A command is issued by a RF test tool which instructs the network device to enter one of one or more different RF modes. In certain embodiments, the network device remains in this RF test mode for a predetermined period of time. In other embodiments, the network device remains in this RF test mode until the power is cycled.

Over the air commands for RF testing

A system and method for controlling the dimming of a lighting element, or other electrical load, that uses a timer synchronized to the AC waveform is disclosed. The timer is set up to repeatedly count at a rate equal to twice the frequency of the AC waveform. An output from the timer logic is asserted when the timer value exceeds a predetermined value, stored in a compare register. This output is connected to the gate of a triac, which controls the passage of current from the AC power source to the electrical load. A capture register is used to determine the temporal relationship between the restart of the timer and the AC waveform. This system and method reduces the real time requirements of an associated processing unit, and improves consistency, thereby reducing flicker.

Light control circuit and method

A method for monitoring a wireless network includes, at a device including a communication interface coupling the device to a wireless network, monitoring messages transmitted between the communication interface and the wireless network, and outputting monitoring data associated with the monitored messages from the device.

Growing community of inventors

Arlington, MA, United States of America

Dewitt Clinton Seward, Iv