Circuit and method for storing information in non-volatile memory during a loss of power event
A data storage circuit for storing data from volatile memory in response to a power loss, the data storage circuit including an input for receiving a power loss signal in response to a power loss from at least one power source, an input configured to receive data from a volatile memory, a single block of non-volatile matrix of memory cells and a driver circuit coupled to said single row of non-volatile matrix of memory cells. The driver circuit is configured to write data to and read data from said single block of non-volatile matrix of memory cells. The single block of non-volatile matrix of memory cells can be provided as a single row electrically erasable programmable read only memory (EEPROM).
1. A data storage circuit for storing data, from volatile memory having a turns count register for storing a value representing an angle of rotation of an object, in response to a power loss, the data storage circuit comprising:
a non-volatile matrix of memory cells comprising an independent subset block of memory cells; and
a controller comprising a plurality of drivers including row and column drivers and an independent driver, the controller configured to:
in the absence of a power loss, write data from the volatile memory to the non-volatile matrix of memory cells using the row and column drivers to perform collective row and column operations; and
in response to receiving a power loss signal write data from said volatile memory to said independent subset block by selectively supplying energy to the independent driver and not the row and column drivers.
2. The data storage circuit of claim 1 wherein the object is the steering wheel of a vehicle.
3. The data storage circuit of claim 1 further comprising an energy storing device, wherein the non-volatile matrix of memory cells forms the memory of an EEPROM, and wherein the row and column drivers are EEPROM row and columns drivers, respectively, and wherein the controller is further configured, in response to receiving the power loss signal, to selectively supply energy from the energy storing device to the independent driver.
4. The data storage circuit of claim 3 wherein the controller is arranged and configured to write data from said volatile memory to said independent subset block in less than about 10 milliseconds.
5. A method of storing data from volatile memory having a turns count register for storing a value representing an angle of rotation of an object, the method comprising:
in response to a controller circuit receiving a signal indicating a loss of power in the volatile memory, from a primary circuit coupled to the volatile memory and comprising a charge pump: writing the data by the controller circuit from the volatile memory into a single row of an EEPROM memory having a plurality of row drivers,
wherein writing the data into the single row includes powering only a single row driver of the plurality by releasing residual power from the charge pump.
6. The method of claim 5 wherein writing the data into the single row by the controller does not utilize a clock signal.