Method and apparatus for preventing unauthorized access to nonvolatile memory in electronic encoders having a voltage level detection circuit
AssigneeMicrochip Technology Incorporated
InventorsKent Hewitt, Willem Smit
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Abstract
According to the present invention, a method is provided for reading data from non-volatile memory in an electronic encoding device such that unauthorized access to the data is prevented. In one embodiment, the method includes the steps of writing a first set of data to the non-volatile memory; generating a voltage detect signal during the writing, the voltage detect signal being representative of a source voltage applied to the non-volatile memory; determining whether the writing was successful by evaluating the voltage detect signal; and reading data from the non-volatile memory responsive to the determination.
Claims6
A method for reading data from non-volatile memory in an electronic encoding device such that unauthorized access to the data is prevented, the method comprising:
- writing a first set of data to the non-volatile memory;
- generating a voltage detect signal during the writing, the voltage detect signal being representative of a source voltage applied to the non-volatile memory;
- determining whether the writing was successful by evaluating the voltage detect signal;
- reading data from the non-volatile memory responsive to the determination.
A system for reading data from non-volatile memory in an electronic encoding device such that unauthorized access to the data is prevented, the system comprising:
- means for writing a first set of data to the non-volatile memory;
- means for generating a voltage detect signal during the writing, the voltage detect signal being representative of a source voltage applied to the non-volatile memory;
- means for determining whether the writing was successful by evaluating the voltage detect signal;
- and
- means for reading data from the non-volatile memory responsive to the determination.
An electronic encoding device comprising:
- a non-volatile memory;
- a controller coupled to the non-volatile memory;
- encoder logic coupled to the non-volatile memory;
- input logic coupled to the controller;
- output logic coupled to the non-volatile memory;
- and
- a voltage level detection circuit coupled to the non-volatile memory, which provides a signal responsive to a non-volatile memory write voltage to enable a read from said non-volatile memory.
A method for reading data from non-volatile memory in an electronic encoding device such that unauthorized access to the data is prevented, the method comprising:
- writing a first set of data to the non-volatile memory;
- generating a voltage detect signal during the writing, the voltage detect signal being representative of a write voltage applied to the non-volatile memory;
- determining whether the writing was successful by evaluating the voltage detect signal;
- reading data from the non-volatile memory responsive to the determination.
An electronic encoding device comprising:
- and non-volatile memory;
- a controller coupled the non-volatile memory;
- encoder logic coupled to the non-volatile memory;
- input logic coupled to the controller;
- output logic coupled to the non-volatile memory;
- and
- a voltage level detection circuit coupled to the non-volatile memory, which provides a signal responsive to a source voltage applied to the non-volatile memory, during writing to said non-volatile memory the signal being enabling of a read from said non-volatile memory.
Dependencies are inferred from the claim text.