Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Philips Electronics North America Corporation

Calto Wong

Rune Hartung Jensen

Dev Datta

Daisuke Takise

Jean-Marc Irazabal

Rudolf H J Bloks

In an electronic device, a first electronic circuit is selectively operated in a selected one of at least two operating modes. A second electronic circuit is selectively operated in a power-up mode and a power-down mode. The second electronic circuit is put into the power-down mode if the first electronic circuit is operated in one of the at least two operating modes.

Power management method for setting clock circuit into power down mode if analog front end circuit is sampling input signals in an electronic device

In a master-slave configuration wherein a sleepmode activation is effected by the cessation of a clocking signal, the need for an analog device or auxiliary clock for detecting the cessation of the clocking signal is obviated by anticipating the cessation of the clock signal. Upon anticipating the cessation of the clock signal, the remaining clock signaling before cessation is used as required to effect a controlled power-down of the slave device. By eliminating the need for an analog clock cessation detector, the process tolerance constraints associated with analog circuitry can be avoided, the reliability and robustness of the design is improved, and the required testing is simplified, thereby reducing the cost of the device. In like manner, the elimination of an auxiliary clock generator reduces the cost and complexity of the device and system, and improves the device and system's overall reliability and testability. In accordance with this invention, the anticipation of the cessation of the clock signal is achieved by monitoring the communications among devices for commands that can be expected to affect the generation of the clock signal.

Sleepmode activation in a slave device

A communication bus system is disclosed. More particularly, the communication bus system includes requesting stations that can issue request packets via a bus and an execution station. The execution station receives the request packets and executes commands modifying the same aspect of a state of the execution station in response to request packets from different stations. The execution station keeps information concerning execution of commands which were last executed in response to request packets for all the different requesting stations. The requesting stations can read this information to determine whether the commands corresponding to their packets are executed, even when other requesting stations are also issuing request packets. Preferably, the execution station shows each requesting station only the information about the execution of commands executed to its own request packets.

Communication bus system with reliable determination of command execution

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Sunnyvale, CA, United States of America

Calto Wong