Automatic detection of battery-backed data integrity in volatile memory
AssigneeRockwell Automation Technologies, Inc.
InventorsWilliam Edward Floro, Frank Joseph Priore
Life of this patent
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Abstract
Battery backed memory for use in an industrial controller allows volatile memory to be retained in instances of line power loss. A method and apparatus are disclosed for providing assurance that sufficient battery voltage was present during the entire power down period to maintain data integrity.
Claims20
A battery backed memory system comprising:
- a first line receiving a source of line voltage;
- volatile solid state memory storing data while receiving a voltage above a critical voltage level;
- a second line receiving a source of battery voltage and providing the battery voltage to the volatile memory during a loss of line voltage;
- a voltage sensor measuring the backup voltage relative to the critical voltage level and providing a signal;
- and
- a microprocessor communicating with the volatile solid state memory and the voltage sensor and executing a program to determine whether the backup voltage was at or below the critical voltage level at any time during the loss of line voltage.
A method of controlling a battery backed memory system including a first line receiving a source of line voltage, volatile solid state memory storing data while receiving a voltage above a critical voltage level, a second line receiving a source of battery voltage to provide backup voltage to the volatile memory during a loss of line voltage, providing a signal measuring the backup voltage relative to the critical voltage level, and a microprocessor communicating with the volatile solid state memory and the voltage sensor, the method comprising the step of:
- executing a program on the microprocessor that determines, based on the signal from the voltage sensor, whether the backup voltage was above the critical voltage level during the entire loss of line voltage.
A method of verifying a status of battery-backed volatile memory that requires a critical voltage level to maintain integrity of data stored therein, the steps comprising:
- (A) providing voltage from a primary source to the volatile memory at a level greater than the critical voltage level;
- (B) providing the volatile memory with backup voltage from a backup source during an interruption of the primary source;
- (C) measuring the backup voltage during the interruption;
- and
- (D) outputting a signal indicating that whether the backup voltage was above the critical voltage level during the entire interruption.
Dependencies are inferred from the claim text.