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  Card deviceRelated Patent Categories: Electrical Computers And Digital Processing Systems: Support, Computer Power Control, Power Conservation, Active/idle Mode ProcessingThe Patent Description & Claims data below is from USPTO Patent Application 20080010478. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to an effective technique to be applied to a card device such as a memory card, an IC card or a multifunction card having a multifunction which is represented by an IC card function and a memory card function. BACKGROUND OF THE INVENTION [0002] Patent Document 1 (JP-A-6-333103 Publication) and Patent Document 2 (JP-A-9-231339 Publication) have described an IC card and a memory card which correspond to a dual voltage as external power sources. These have described that a voltage of 3.3V or 5V is supplied from an outside, and the voltage of 5V is dropped to 3.3V by a regulator and the voltage of 3.3V is exactly supplied to an internal circuit. SUMMARY OF THE INVENTION [0003] The inventor investigated a reduction in a power consumption of a card device. When a card controller of the card device does not carry out a command processing from a host, a microcomputer of the card controller is brought into a sleep state so that a consumed power in a standby mode (a low consumed power mode) can be reduced. Although the microcomputer is brought into the sleep state in the standby mode of the card device, a regulator provided in the card controller is continuously operated. Correspondingly, the power is consumed. The consumed power of a series regulator occupies most of the consumed power in the standby state. Therefore, the inventor has found that the continuous operation of the series regulator disturbs a reduction in the consumed power. [0004] It is a typical object of the invention to reduce the consumed power in the low consumed power state of the card device. [0005] The above and other objects and novel features of the invention will be apparent from the description of the specification and the accompanying drawings. [0006] Brief description will be given to the summary of the typical invention disclosed in the application. [0007] [1] A card device comprises a regulator, a first internal circuit and a second internal circuit, and the regulator supplies, to the second internal circuit, an internal voltage generated by dropping an external voltage when the external voltage is high, and exactly supplies the external voltage as an internal voltage to the second internal circuit when the external voltage is low, the external voltage is supplied as an operating power source to the first internal circuit and a transition to a low consumed power state is carried out if a command is not input for a certain period. The card device stops the operation of the regulator and suppresses the supply of the internal voltage to the second internal circuit in the transition to the low consumed power state. [0008] Accordingly, it is possible to suppress a power consumption in each of the regulator and the second internal circuit in the card device in the low consumed power state. [0009] As a typically specific configuration of the invention, when a return from the low consumed power state to the operation state is performed, the first internal circuit can restart the operation of the regulator to supply the internal voltage to the second internal circuit. It is sufficient that the first internal circuit is operated within at least this range. Consequently, a power consumption is very small. Since the first internal circuit is required to have a breakdown voltage for the external voltage which is high, moreover, a logical scale thereof can be expected to be usually reduced. Also in this respect, the power consumption of the first internal circuit is small. [0010] As another typically specific configuration of the invention, the regulator has a voltage detecting circuit for deciding whether an external voltage is high or not and a reference voltage generating circuit for generating a reference-voltage to be utilized when dropping the external voltage, and a stop of the operation of the regulator in the transition to the low consumed power state is set to be that of operations of the voltage detecting circuit and the reference voltage generating circuit. [0011] As a further typically specific configuration of the invention, the second internal circuit has a microcomputer and the transition to the low consumed power state triggers a transition to a sleep state of the microcomputer. [0012] The first internal circuit operates the regulator in response to a command input and restarts the supply of the internal voltage to the second internal circuit in the low consumed power state. The microcomputer detects the supply of the operating power source in the sleep state, thereby carrying out a power-ON reset processing. [0013] The first internal circuit has a storage region for saying and the microcomputer saves necessary internal information for a return of an internal state in the storage region for saving in the transition to the sleep state. The microcomputer returns necessary internal information retained in the storage region for saving in the power-ON reset processing. It is possible to shorten a time required for the transition from the sleep state to the operation state. [0014] [2] In a card device having another representation configuration, a regulator generates an internal voltage by dropping an external voltage supplied from an outside and supplies the internal voltage to an internal circuit when the external voltage is high, and exactly supplies the external voltage as the internal voltage to the internal circuit when the external voltage is low, and a transition to a low consumed power state is carried out if a command is not input for a certain period. The card device stops the operation of the regulator and stops a supply of a power to a part of the internal circuit, and exactly supplies the external voltage as the internal voltage to the other portions of the internal circuit in a transition from the operation state to the low consumed power state. [0015] As a typically specific configuration of the invention, the part of the internal circuit in which the supply of the power is stopped in the transition from the operation state to the low consumed power state includes a microcomputer to be brought into a sleep state. The other portions of the internal circuit have a storage region for saving and the microcomputer saves necessary internal information for a return of an internal state in the storage region for saving in a transition to the sleep state. The microcomputer carries out the return of the necessary internal information retained in the storage region for saving in a power-ON reset processing. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a block diagram showing a memory card according to an example of a card device, [0017] FIG. 2 is a circuit diagram illustrating a structure of a regulator, [0018] FIG. 3 is a operational timing chart showing a transition from an active state to a standby state and a transition from the standby state to the active state in the memory card, [0019] FIG. 4 is a flowchart showing the transition from the active state to the standby state and the transition from the standby state to the active state in the memory card, and [0020] FIG. 5 is an explanatory diagram showing an operation of the memory card in accordance with the flowchart of FIG. 4. Continue reading... Full patent description for Card device Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Card device patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Card device or other areas of interest. ### Previous Patent Application: Recording apparatus and method for controlling the recording apparatus Next Patent Application: Method and system for dynamic temperature compensation for a source-synchronous interface Industry Class: Electrical computers and digital processing systems: support ### FreshPatents.com Support Thank you for viewing the Card device patent info. IP-related news and info Results in 0.12317 seconds Other interesting Feshpatents.com categories: Accenture , Agouron Pharmaceuticals , Amgen , AT&T , Bausch & Lomb , Callaway Golf |
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