Siliconsystems, Inc.

Other

Texas Instruments Corporation

Charles C Austin

Bertram John White

Jeff Harth

Kevin Feshangchi

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. The overlaid data memory is not accessible while it is overlaid. Then, after completing transfers, the peripheral registers can be relocated elsewhere so that the underlying internal data memory is recovered. The underlying data memory is not disturbed when writing to the overlaying peripheral registers.

Relocatable overland peripheral paging

The present invention provides a system for controlling current through inductive elements by automatically switching between a pulse width modulation mode and a linear mode, depending upon the current demands of the inductive elements. A time-base circuit provides periodic pulses that allow current to flow through an inductive device. The current through the inductive device increases over time. If the current through the inductive device exceeds a specified value, the current is shut off until the next pulse from the time-base circuit. After the power supply current has been shut off, current through the inductive device continues to flow through flyback diodes, gradually decreasing over time. Another pulse is provided by the time-base circuit before the current is allowed to reach zero. By controlling the duration and rate of increase and decrease of current through the inductive device, a method of current control for inductive elements has been provided.

Control system for motors and inductive loads

A circuit to provide adaptive commutation delay for multi-pole brushless DC motors. The circuit adjusts the commutation delay as a function of the rotational speed of the motor to maximize motor torque and minimize power consumption. Unlike the prior art, the circuit avoids the need for complex circuitry or external components. The circuit may be implemented entirely within a single integrated circuit. The circuit includes a back-EMF sensing input, an oscillator, a voltage holding and proportioning circuit, one or more comparators and, optionally, an external control circuit. The back-EMF sensing input controls the operation of the oscillator. The voltage holding and proportioning circuit processes the oscillator output and provides outputs which are compared by the comparators. The comparators produce commutation delay signals and, optionally, other signals. The circuit also allows adjustment to compensate for non-ideal back-EMF-to-rotor-position correspondence or fixed time delays inherent in the commutation process.

Adaptive commutation delay for multi-pole brushless DC motors

The present invention provides driver circuitry for commutated inductive loads, and in particular, inductive loads employed in multi-pole DC brushless motors. The preferred embodiment of the present invention typically implements three pull-up and three pull-down drivers for motor control. The pull-down driver circuit described in the present invention can be configured to be adjusted by an external component of the integrated circuit implementation in order for controlling turn-off transients. Voltage transients due to changes in load current in the control loop of the pull-down driver circuit can be minimized or deterministically controlled by controlling the rate of change of the input voltage. For the case of when the load current is to be completely switched from one inductor to another inductor, an additional unity gain buffer coupled to the input voltage is inserted into the control loop of the pull-down driver circuit for reducing the voltage transients that can result. The output voltage rise and fall times of the pull-up driver circuit of the present invention can be controlled by means of an accurate clock rate, a capacitance ratio value, an arbitrary voltage supply or by any combination of the above means. The present invention also provides circuitry for controlling the pull-up driver circuit and the pull-down driver circuits as required to assert the floating operation and as well dynamic breaking operation. The present invention is able to assert these operations by operating from either the power supply or from an energy storage capacitor that is charged to a value closely approximating the power supply voltage should the power supply be removed.

Driver circuitry for commutated inductive loads

A TTL/CMOS interface circuit comprised entirely of CMOS components. An input gain stage comprised of transistors of a single conductivity type is provided whose gain is established by the ratio of the geometric size of the transistors. In the preferred embodiment of the present invention, the input gain stage is comprised of N channel transistors to a void process related mismatches. An inverter stage has a switching threshold set to optimally operate with the output of the input gain stage. The voltage at the inverter stage is tied to the power supply voltage to supply an upper voltage limit. In order to provide for zero power operation for input signals close the value of the supply voltage, a transistor is provided to cut current flow in the input stage for input signals within a threshold voltage of the supply voltage. The present circuit may also be utilized as to allow zero power operation for input signals close to ground.

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Mission Viejo, CA, United States of America

Charles C Austin