NON-CONTACT COMMUNICATION DEVICE
First Claim
1. A non-contact communication device which is driven by a battery and conducts non-contact communication by adjusting a resonance frequency of an antenna circuit using data for resonance frequency adjustment, the non-contact communication device comprising:
- a memory section that stores the data for resonance frequency adjustment;
a control section that is reset by a first reset signal issued at the time when a voltage of the battery falls below a first threshold value;
a register section that temporarily holds data and is reset by a second reset signal issued at the time when the voltage of the battery falls below a second threshold value lower than the first threshold value; and
the antenna circuit whose resonance frequency is adjusted by the data temporarily held in the register section,wherein the control section downloads the data for resonance frequency adjustment from the memory section to the register section as the data before the control section is reset by the first reset signal, and the resonance frequency of the antenna circuit is adjusted using the data for resonance frequency adjustment previously downloaded to the register section in a state that the control section is reset by the first reset signal.
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Accused Products
Abstract
A problem of the invention is to provide a non-contact communication device capable of conducting non-contact communication even when a control section cannot be operated a drop in a battery voltage or a reset. A memory element (15) for storing resonance frequency adjustment data and communication condition data, and a setting register (2) capable of temporarily holding the resonance frequency adjustment data and the communication condition data from the memory element (15) to the setting register (2) before a reset by a CPU (17). When the CPU (17) is reset by a CPU reset signal, the resonance frequency adjusting data downloaded to the setting register (2) are used to adjust the resonance frequency of an antenna circuit. Thus, non-contact communication can be performed even when the CPU cannot operate because of a drop in the battery voltage or a reset.
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Citations
2 Claims
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1. A non-contact communication device which is driven by a battery and conducts non-contact communication by adjusting a resonance frequency of an antenna circuit using data for resonance frequency adjustment, the non-contact communication device comprising:
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a memory section that stores the data for resonance frequency adjustment; a control section that is reset by a first reset signal issued at the time when a voltage of the battery falls below a first threshold value; a register section that temporarily holds data and is reset by a second reset signal issued at the time when the voltage of the battery falls below a second threshold value lower than the first threshold value; and the antenna circuit whose resonance frequency is adjusted by the data temporarily held in the register section, wherein the control section downloads the data for resonance frequency adjustment from the memory section to the register section as the data before the control section is reset by the first reset signal, and the resonance frequency of the antenna circuit is adjusted using the data for resonance frequency adjustment previously downloaded to the register section in a state that the control section is reset by the first reset signal. - View Dependent Claims (2)
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Specification