The steering angle of a vehicle is monitored using position sensors of an electric motor of an electric power assisted steering (EPAS) system. A position of the electric motor corresponding to the straight-ahead, center position of the steering system is stored in non-volatile memory during a steering calibration procedure, such as an end-of-line calibration in a vehicle assembly plant. Following power loss due to a dead battery, a steering angle zeroing procedure performed in a vehicle stability control (VSC) system generates a center position with enough accuracy to be within one electrical cycle of the motor. The pre-stored electric motor position is then used to determine the electrical cycle where the center position was located, and accurate monitoring of steering angle is resumed.

Recovery of calibrated center steering position after loss of battery power

A memory system (10) capable of being configured for optimum performance after fabrication using control parameters stored in non-volatile data storage units (12A). The system includes an array of memory cells (12) separate from the data storage units (12A), arranged in a multiplicity of rows and columns, with each cell located in one of the rows being coupled to a common word line and with each cell located in one of the columns being coupled to a common bit line. Control circuitry (19) for controlling memory operations such as programming the memory cells and reading the memory cells when the memory system is in a normal mode of operation. The non-volatile data storage units (12A) store control parameter data used by the control means for controlling the memory operations, with the control parameters being modifiable when the memory system is placed in an alternative mode of operation as opposed the normal mode of operation. Once the memory has been fabricated and characterized, the control parameters can be selected for optimum memory performance and loaded into the data storage units.

Memory system having programmable control parameters

A non-volatile data storage unit having a data input and a volatile memory device for storing data. The volatile memory device is preferably a latch circuit made up of a pair of cross-coupled inverter circuits which store the data in complementary form. A non-volatile memory device, such as a pair of flash memory cells, is included which also store data in complementary form. Control circuitry is provided for controlling the operation of the data storage unit, including circuitry for transferring data from the data input to the volatile memory device and circuitry for programming the non-volatile memory device with data from the volatile memory device. The storage unit also preferably includes circuitry for transferring data stored in the non-volatile memory device to the volatile memory device, with such transfer typically taking place after an interruption of power to the storage unit.

Non-volatile data storage unit and method of controlling same

A memory system (10) capable of being configured for optimum operation after fabrication and method of controlling the same. The system includes an array of memory cells arranged in a multiplicity of rows and a multiplicity of columns, with each cell located in one of the rows being coupled to a common word line and with each cell located in one of the columns being coupled to a common bit line. Control circuitry (19) is included for controlling memory operations, with the memory operations (16) including programming the memory cells, reading the memory cells and preferably programming the cells. A plurality of non-volatile data storage units (12A) are provided for storing control parameter data used by the controlling means for controlling the memory operations. Such control parameters may include, for example, parameters for adjusting the magnitude and duration of voltage pulses applied to the memory (10) for carrying out programming and erasing operations.

Memory system having non-volatile data storage structure for memory control parameters and method

A method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Controller for a motor and a method of controlling the motor

An output of a power-on-reset (POR) circuit is coupled to another circuit which needs to have the logic states thereof reset during each time a power supply used to power same is switched on. The POR circuit includes a first input circuit for generating an output signal that tracks the power supply output voltage Vdd approximately a first predetermined threshold below Vdd, as Vdd ramps up and further includes a second input circuit which generates an output signal which tracks approximately a second predetermined threshold above a second fixed voltage level, e.g., ground. The POR circuit further includes a comparator which compares the output signals from the first and second input circuits and switches an output signal thereof from a first to a second logic state once the input circuit output signals cross each other. A buffer is typically coupled to the output of the comparator to limit loading on same so as not to affect the comparator switching point.

Power-on-reset (POR) circuit having power supply rise time independence

A noise tolerant motor position monitoring circuit having a digital filter section receives and filters noisy hall effect sensor inputs for use in determining rotational motor position. The motor position monitoring circuit exchanges information and instructions with a microprocessor which utilizes the motor position information to calculate motor distance traveled, motor speed, etc. The hall effect sensor signals are noisy due to the particular environment in which the sensed motor is placed, such as in industrial process and automotive applications. Each monitored segment of rotation corresponds to the motor rotational switching sequence of a motor driver circuit, a digital counter generates a running total rotational count and increments or decrements the total count depending upon the direction of motor rotation. A programmable digital filter time constant is generated and, via state machine operation, a hall sensor signal duration range is implemented for differentiating valid motor rotation signals from spurious noise signals. The desired operating range is programmably altered via the microprocessor and programmable digital filter time constant to allow the motor position monitoring circuit to operate for a broad range of motors having divergent characteristics.

Noise tolerant brushless motor position monitoring apparatus and method

A fault detection circuit monitors voltage drops associated with phase windings of a brushed or brushless reversible multi-phase motor and compares them with reference voltages to determine if the motor is out of normal operating range parameters and if a valid fault condition exists. The fault detection circuit-is included in a motor control circuit and is configurable for use with a wide variety of motors having a broad range of load characteristics. The fault detection circuit includes a programmable clock generator which generates time delays for masking faults detected during start-up and during motor phase sequencing. The fault detection circuit thereby avoids transient and spurious faults and prevents the unnecessary termination of motor operation. The length of the mask time delay required for effective fault detection operation depends on the load characteristics of the selected motor. The parameters defining the mask time delay are selected to match the time delay to the characteristics of the motor. The parameters are downloaded to the fault detection circuit from an external source.

On and off state fault detection circuit for a multi-phase brushed or brushless DC motor

A programmable apparatus and method are provided for processing multiple routines so as to realize different timing resolutions. The apparatus includes a programmable timer device equipped with instruction memory for storing programmed instructions and programmable memory for storing a plurality of program counter entries, each dedicated to a corresponding routine. A plurality of program loops are provided, each of which includes a selected number of program counter entries. One entry from each of the program loops is sequentially selected and a corresponding instruction is executed. The number of entries dedicated to each program loop, or subloop, is selected so that different routines may realize different timing resolutions. Furthermore, program subloop entries could be repeated one or more times within a given loop to further improve (make finer) the timing resolution.

David Wayne Stringfellow

Papers

Power-on-reset (POR) circuit having power supply rise time independence

Noise tolerant brushless motor position monitoring apparatus and method

On and off state fault detection circuit for a multi-phase brushed or brushless DC motor

Microprogrammed timer processor having a variable loop resolution architecture