Standard Microsystems Corporation

Robert W Schoepflin

Eileen Marando

Richard Wahler

John D Virzi

Leonid A Bekker

Ronald W Streiber

Donald D Noviello

A system may include a PWM generator and control logic. The PWM generator is configured to generate a PWM signal having a duty cycle dependent on a duty cycle value generated by the control logic. The control logic is configured to generate the duty cycle value to have a piecewise linear relationship with temperature such that at least two of a plurality of linear segments defined by the piecewise linear relationship have different slopes. In some embodiments, the piecewise linear relationship may be continuous.

Generating a PWM signal dependent on a duty cycle having a piecewise linear relationship with temperature

System and method for controlling a fan. A value may be received for controlling the fan. The value may include a first number of bits and may correspond to a linear function of temperature. A first value may be determined using a first number of bits of the value. A modification to the first value may be determined based on a second number of bits of the value. A new output value may be generated based on the first value and the modification to the first value. The new output value may correspond to a first nonlinear function of temperature. The new output value may be provided for controlling the fan.

Generating a nonlinear function for fan control

A fan control system in which a sensor selection block having a number of sensor inputs may be combined with an autofan block having a number of zone inputs, where the number of sensor inputs is greater than the number of zone inputs. Each one of the sensor inputs of the sensor selection block may have a corresponding sensor parameter input. The sensor selection block may be configured to map a subset of the sensor inputs with corresponding sensor parameter inputs to the autofan block. Each zone input and corresponding zone parameter input of the autofan block may receive a corresponding one of the subset of the sensor inputs with corresponding sensor parameter inputs, respectively. The autofan block may have a number of pulse width modulated (PWM) outputs that may be calculated according to the autofan block zone inputs and zone parameter inputs.

Mapping a plurality of sensors to respective zones in a fan control system

A double buffered flash bank. In one embodiment, a flash interface may be programmed by a register interface with a first set of data while a second set of data is being written to the register interface. In one embodiment, flash banks may be programmed in parallel using latched register interfaces. For example, while data from a first register interface is being written to the first flash bank and data from a second register interface is being written to a second flash bank, new data may be written to the first register interface and to the second register interface. The new data may then be written from the first register interface to the first flash bank and from the second register interface to the second flash bank.

Double buffered flash programming

A system and method for controlling a fan is disclosed. A single control signal value for controlling the fan, such as a single PWM duty cycle value for a corresponding PWM generator output powering the fan, may be calculated by combining sensor data from two or more temperature zones. In one embodiment, the single PWM duty cycle value may be determined based on the temperature in a first zone, for example the CPU, with an additional factor based on the temperature in a second zone, for example the ambient temperature of a PC enclosure. In one embodiment, the final single PWM value is determined by adding an offset value to a PWM value calculated based on the current temperature of the first zone, where the offset value is obtained by calculating a first &#x394;PWM factor for the first zone, and using the first &#x394;PWM factor, in conjunction with a scaling factor, to weight a second &#x394;PWM factor calculated for the second zone.

Autofan combination of zones

Piecewise linear control of the duty cycle of a pulse width modulated signal

A system may include control logic and a PWM generator configured to generate a PWM (Pulse Width Modulated) signal. The PWM generator is configured to generate the duty cycle of the PWM signal dependent on a duty cycle value generated by the control logic. The control logic stores an inverse focal point value and is configured to generate the duty cycle value by processing the inverse focal point value and a temperature value indicating a current temperature according to the equation of a parabola.

Parabolic control of the duty cycle of a pulse width modulated signal

A system may include a tachometer reading unit and a PWM (Pulse Width Modulated) signal generator configured to generate a PWM signal. The tachometer reading unit may be configured to obtain a tachometer reading from a tachometer signal generated by a device powered by the PWM signal. The tachometer reading unit includes a register configured to store a value indicative of a maximum stretching duration. The tachometer reading unit is configured to update the register in response to receiving a new value of the maximum stretching duration. The tachometer reading unit may be configured to control the PWM signal generator to stretch a pulse in the PWM signal and to not stretch the pulse longer than the maximum stretching duration indicated by the register. The tachometer reading unit is configured to obtain the tachometer reading during the stretched pulse in the PWM signal.

Growing community of inventors

Port Jefferson, NY, United States of America

Robert W Schoepflin