Abstract: Apparatus for flexibly locating the data page on which the peripheral registers are located. External hardware contentions are eliminated because the peripheral registers can be relocated anywhere in the system address space. Hardware design is therefore much more flexible. Further, because the present invention allows peripheral registers to overlay internal data memory, data transfers can be carried out between data and peripherals using the same data page pointer. No intermediate pointer loading operations are required and memory operations to the peripheral registers can be carried out at maximum speed. The present invention allows peripheral registers to overlay data memory in a manner that permits the overlaid memory to be recovered and used for other purposes. Processor program code can be designed to overlay internal data memory with the peripheral registers while performing data transfers between the data memory and the peripheral registers.

Abstract: A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.

Abstract: A method for starting a sensorless brushless DC motor. The present invention uses the physical equations of motion of the motor to calculate commutation advancement rates during the motor's start-up period. An algorithm initially calculates the commutation advancement rates for the motor's maximum theoretical accelleration. The commutation applied to the motor is advanced through a predetermined number of commutation states using these maximum rates. After the predetermined number of commutation states have been applied, the speed of the motor is checked to determine whether the motor is spinning at a high enough speed to permit use of the motor's normal commutation state advancement system. If the motor is not up to speed, the rate at which the commutation states are advanced is incrementally decreased until satisfactory operation of the motor is obtained or until motor failure is diagnosed and starting is aborted.

Abstract: A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.

Abstract: A method and apparatus to commutate the drive voltages of a brushless DC motor without sensors. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to the transformed reference. In an extra measure of efficiency, it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.