Boots – shoes – and leggings
Patent
1996-08-16
1998-06-02
Trammell, James P.
Boots, shoes, and leggings
307 65, 365229, G05B 902
Patent
active
057610614
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates generally to a data processing medium. More particularly, this invention relates to a circuit for backing up the semiconductor element of a data processing medium in replacing the battery for the data processing medium, and to a data processing medium with the backup circuit. Additionally, this invention relates to a data processing system containing the data processing medium and a data processing unit.
BACKGROUND OF THE INVENTION
In general, a data processing medium such as a memory card is supplied with a driving voltage from a data processing unit (typically, a personal computer and its peripheral equipment) in which the medium is to be installed. When the supply of the voltage to a memory card using a static random access memory (hereinafter, abbreviated as an S-RAM) as the data storage element is cut off, the stored data will be lost.
Accordingly, to back up the stored data in the S-RAM of a memory card, various backup circuits and circuit systems have been proposed.
As one known example, there is a circuit in which the voltage supply line of a memory card is connected to a parallel combination of the main battery acting as a first backup means, an auxiliary battery acting as a second backup means (a large capacitor), and an S-RAM. In this circuit, while the memory card is being removed from the data processing unit, the main battery supplies a voltage to the S-RAM to retain the stored data in the S-RAM. When the main battery is replaced, the large capacitor supplies a voltage for retaining the stored data in the S-RAM.
Generally, when data is read from the S-RAM, a higher voltage than that of the main battery is supplied from an external power supply (a power supply build in the data processing unit) to the S-RAM through the voltage supply line. In the case of a circuit using a conventional large capacitor, the voltage from the external power supply is also supplied to the large capacitor. This permits a charging current to flow into the large capacitor at the same time that an operating current flows into the S-RAM.
The charging current to the large capacitor is a wasteful load to the external power supply. The large capacitor is required to have a high withstand voltage so as to withstand the voltage from the external power-supply line. Therefore, it is necessary to use a relatively expensive large capacitor for the conventional circuit.
As another known example, there is a circuit system in which the current line of the power supply for an IC card is connected to a parallel combination of the main battery acting as a first backup means, a rechargeable auxiliary battery (a lithium battery) acting as a second backup means, and an S-RAM, with a diode and a constant-voltage circuit connected between the power supply and the lithium battery. In this circuit system, the lithium battery backs up the S-RAM when the main battery is replaced.
In the conventional circuit system, however, the lithium battery is charged only when a high voltage for operating the S-RAM, for example, a +5 voltage is applied from the power supply. Therefore, before the replacement of the main battery, the lithium battery must be charged from the power supply. Furthermore, because the conventional circuit system contains a constant-voltage source, its design and arrangement are complex.
Additionally, in the conventional circuit or circuit system, each time that the power supply applies a voltage to the S-RAM, the auxiliary battery (the large capacitor or lithium battery) is also charged. However, since the number of charges and discharges is limited for the large capacitor or lithium battery, frequent charging and discharging degrades its characteristics.
SUMMARY OF THE INVENTION
A general object of the present invention is to solve problems peculiar to the above-described conventional circuit and circuit system. Specifically, the object of the invention is to provide a data processing medium, its backup circuit, and a data processing system which prevent a charging current fro
REFERENCES:
patent: 3816768 (1974-06-01), Stein
patent: 3982141 (1976-09-01), Copeland, III
patent: 4492876 (1985-01-01), Colbert et al.
patent: 4677311 (1987-06-01), Morita
patent: 5033882 (1991-07-01), Vanderpool et al.
patent: 5152697 (1992-10-01), Abe et al.
Berg Technology Inc.
Trammell James P.
LandOfFree
Data processing medium, its backup circuit, and data processing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data processing medium, its backup circuit, and data processing , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data processing medium, its backup circuit, and data processing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1468019