Freescale Semiconductor,inc.

Nxp Usa, Inc.

John Matthew Hall

William Ernest Edwards

John M Pigott

Randall C Gray

Fred T Brauchler

Mike Robert Garrard

Michael Robert Garrard

A control methodology and apparatus for an engine suitable for use in capacitor discharge ignition systems for internal combustion engines or brushless DC motors is provided, which make use of a simple logic block to determine for instance an ignition timing advance angle or duty cycle signal based on actual engine speed versus engine control parameter data stored in a table, which is a read-only memory, preferably configurable. To minimize memory space, a small number of values of engine control parameter versus engine speed are stored in the table and the logic block determines the required engine control signal for a measured value of engine speed by an interpolation process, preferably linear interpolation.

Method and apparatus for determining a value of a variable parameter

An ignition control device having an Electronic Fuel Injection mode and a Capacitive Discharge ignition mode is described. The ignition control device comprises: an output for providing an output voltage, connected or connectable to a load, the load being a fuel injection actuator of an EFI system or an ignition capacitor of a CDI system; and a driver unit connected to the output, for driving the output voltage from a low level to a high level and from the high level to the low level in dependence on an input signal, each transition of the output voltage from the low level to the high level having a low-to-high transition time which is longer for the CDI mode than for the EFI mode.

Ignition control device having an electronic fuel injection (EFI) mode and a capacitive discharge ignition (CDI) mode

An integrated circuit having normal and special operating modes includes a mode entry interlock () which is enabled by an initialization command and an externally supplied voltage at a first I/O terminal () to detect a conflict at the I/O terminal for reducing the likelihood of inadvertent entry into the special operating mode. The mode entry interlock also includes a second I/O terminal () for receiving a disassociated software command to enter into the special operating mode, and mode control logic () for evaluating the received software command against any detected conflict at the I/O terminal to generate a special operating mode enable signal in response to receiving the first and second input signals only when the detected logic state conflicts with the first logic state.

Test mode entry interlock

An interface for processing a variable reluctance sensor signal provided by a variable reluctance sensor including an integrator, an arming comparator and a detect circuit. The integrator includes an input for receiving the variable reluctance sensor signal and an output providing an integrated signal indicative of total flux change of the variable reluctance sensor. The arming comparator compares the integrated signal with a predetermined arming threshold and provides an armed signal indicative thereof. The detect circuit provides a reset signal after the armed signal is provided to reset the integrator. A corresponding method of processing the variable reluctance sensor signal is also described.

Variable reluctance sensor interface with integration based arming threshold

A variable reluctance sensor system for processing a variable reluctance sensor signal including an arming comparator and an arming circuit. The arming comparator compares the variable reluctance sensor signal with an arming threshold which decreases proportional to 1/t from a predetermined maximum level and asserts an armed signal when the variable reluctance sensor signal reaches the arming threshold. The arming threshold may be decreased based on a scaling factor multiplied by 1/t to ensure detection of each pulse of the variable reluctance sensor signal. The arming threshold may decrease to a predetermined minimum level sufficiently low to intersect the variable reluctance sensor signal and sufficiently high relative to an expected noise level. The arming threshold is reset in response to a timing event, such as zero crossing of the variable reluctance sensor signal.

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Chelsea, MI, United States of America

John Matthew Hall