US 5,297,119 AGranted

Data storage apparatus

AssigneeCasio Computer Co., Ltd.

InventorsNobuyuki Tonegawa, Syuji Yamaguchi

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Abstract

Data input through a key switch is displayed on a liquid crystal display and is stored in an EEPROM. The data stored in the EEPROM is immediately read out to check whether the read data coincide with the input data. If the data stored in the EEPROM and read out therefrom does not coincide with the input data, the input data is stored again. If the input data cannot be stored in the EEPROM after storage operation is performed a predetermined number of times, a CPU determines, on the basis of a signal from a battery voltage detecting circuit, whether a voltage applied from a power supply circuit to the EEPROM exceeds a predetermined voltage. On the basis of this determination result, the CPU causes the liquid crystal display to display a cause for the disabled storage operation with respect to the EEPROM.

Claims23

Dependent claims

A data storage apparatus comprising:

a battery power supply;
data input means for inputting data;
nonvolatile memory means, to which a power supply voltage is applied from said battery power supply, for storing the data input by said data input means;
and
storage control means for storing the data input by said data input means in said nonvolatile memory means by control of microprograms, said storage control means comprising:
write determination means for determining whether the data input by said data input means is correctly written in said nonvolatile memory means;
first informing means for, when said write determination means determines that the data is correctly written, informing that the data is correctly written;
voltage detecting means for detecting whether a voltage of said battery power supply is lower than a predetermined voltage immediately after said write determination means determines that the data is not correctly written;
second informing means for, when said voltage detecting means detects that the voltage of said battery power supply is lower than the predetermined voltage, informing that the data is not written because of a decrease in voltage of said battery power supply;
and
third informing means for, when said voltage detecting means detects that the voltage of said battery power supply is higher than the predetermined voltage, giving information different from information from said second informing means.

8 more elements

A data storage apparatus comprising:

a battery power supply;
data input means for inputting data;
volatile memory means for storing the data input by said data input means;
nonvolatile memory means, operated by a power supply voltage from said battery power supply, for storing the data input means;
selection switch means for selecting one of said volatile memory means and said nonvolatile memory means in which the data input by said data input means is stored;
first storage control means for causing said volatile memory means to store the data input by said data input means when said volatile memory means is selected by said selection switch means;
second storage control means for causing said nonvolatile memory means to store the data input by said data input means when said nonvolatile memory means is selected by said selection switch means;
write determination means for determining whether the data is correctly written in said nonvolatile memory means by said second storage control means;
first informing means for, when said write determination means determines that the data is correctly written, informing that the data is correctly written;
voltage detecting means for detecting a voltage of said battery power supply when said write determination means determines that the data cannot be correctly written;
second informing means for, when said voltage detecting means detecting that the voltage of said battery power supply is lower than the predetermined voltage, informing that the data is not written because of a decrease in voltage of said battery power supply;
and
third informing means for, when said voltage detecting means detects that the voltage of said battery power supply is higher than the predetermined voltage, giving information different from information from said second informing means.

10 more elements

Dependencies are inferred from the claim text.