Data processing medium, its backup circuit, and data processing system
First Claim
1. A data processing medium containing a semiconductor element which can at least store data, comprising:
- a voltage input terminal which can be connected to an external power supply and from which a voltage supply line is extended to supply a voltage from the external power supply so as to operate the semiconductor element;
first detachable backup means which has positive and a negative electrode, the positive electrode being operatively coupled to the semiconductor element via the voltage supply line, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal;
second backup means which has a positive and a negative electrode, the positive electrode being electrically connected to the positive electrode of the first backup means so as to be charged from the first backup means, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal and the first backup means is detached; and
charging prevention means provided between the junction of the positive electrode of the first backup means and the positive electrode of the second backup means and the external power supply so that the second backup means may not be charged from the external power supply.
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Accused Products
Abstract
There is disclosed a backup circuit for a memory card where the stored data in an S-RAM is retained even when the card (2) contains a main battery (18) whose output voltage is 3.3 V, an auxiliary battery (20), and a charging prevention diode (22). The main battery (18) and the auxiliary battery (20) are connected in parallel. Between their junction (28) and a built-in power supply (8) of a personal computer (4), the charging prevention diode (22) is provided. Because the second diode (22) is placed in a forward direction running from the junction (28) toward a voltage supply line (10), the auxiliary battery (20) is charged only from the main battery (18), and a charging current from the built-in power supply (8) does not flow into the auxiliary battery (20).
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Citations
19 Claims
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1. A data processing medium containing a semiconductor element which can at least store data, comprising:
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a voltage input terminal which can be connected to an external power supply and from which a voltage supply line is extended to supply a voltage from the external power supply so as to operate the semiconductor element; first detachable backup means which has positive and a negative electrode, the positive electrode being operatively coupled to the semiconductor element via the voltage supply line, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal; second backup means which has a positive and a negative electrode, the positive electrode being electrically connected to the positive electrode of the first backup means so as to be charged from the first backup means, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal and the first backup means is detached; and charging prevention means provided between the junction of the positive electrode of the first backup means and the positive electrode of the second backup means and the external power supply so that the second backup means may not be charged from the external power supply. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A backup circuit for backing up stored data in a semiconductor element in a data processing medium comprising a semiconductor element which can at least store data and a voltage input terminal which can be connected to an external power supply and from which a voltage supply line is extended to supply a voltage from the external power supply so as to operate the semiconductor element, said backup circuit comprising:
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first backup means which is detachable from the data processing medium, has a positive and a negative electrode, the positive electrode being electrically connected to the semiconductor element via the voltage supply line, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal; second backup means which is detachable from the data processing medium, has a positive and a negative electrode, the positive electrode being electrically connected to the positive electrode of the first backup means so as to be charged from the first backup means, and which backs up the stored data in the semiconductor element during the time when the external power supply is disconnected from the voltage input terminal and the first backup means is detached from the data processing medium; and charging prevention means provided between the junction of the positive electrode of the first backup means and the positive electrode of the second backup means and the external power supply so that the second backup means may not be charged from the external power supply. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A data processing system comprising a data processing medium containing a semiconductor element which can at least store data and a data processing unit to which the data processing medium is to be connected, data exchange being effected between the data processing medium and the data processing unit, wherein said data processing unit comprises:
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a power supply for supplying a voltage; and transmission/reception means for transmitting and/or receiving data to and from said semiconductor element of said data processing medium; and said data processing medium comprises; a voltage input terminal which can be connected to said power supply of said data processing unit and from which a voltage supply line is extended to supply a voltage from said power supply so as to operate said semiconductor element; first detachable backup means which has a positive and a negative electrode, the positive electrode being connected to said semiconductor element via the voltage supply line, and which backs up the stored data in said semiconductor element during the time when said power supply is disconnected from the voltage input terminal; second backup means which has a positive and a negative electrode, the positive electrode being electrically connected in parallel to the positive electrode of the first backup means so as to be charged from the first backup means, and which backs up the stored data in said semiconductor element during the time when said power supply is disconnected from the voltage input terminal and the first backup means is detached; and charging prevention means provided between the junction of the positive electrode of the first backup means and the positive electrode of the second backup means and the voltage input terminal so that the second backup means may not be charged from said power supply. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification