Abstract: An apparatus for determining the validity of a data signal communicated between two microprocessors by a dual port RAM includes a sender for providing a data signal and an initialization status indicator and a dual port RAM in communication with the sender for receiving the data signal and the initialization status indicator. The RAM has a first location for storing the data signal and a second location for storing the initialization status indicator. The sender performs initialization on the RAM at the beginning of a data transfer cycle which includes a plurality of data transfer from the sender to a receiver. The sender updates the initialization status indicator as the initialization progresses. The receiver reads the initialization status of the RAM from the second location and subsequently reads the data signal from the first location in association with the initialization status of the RAM.

Abstract: A method includes diagnosing a solenoid circuit to determine if the circuit has begun to degrade. By measuring characteristics associated with the electrical waveform, it is determined if the characteristics of a solenoid circuit are different from the previously measured characteristics of the circuit, or of a known functioning circuit.

Abstract: An apparatus for determining the validity of a data signal communicated between two microprocessors by a dual port random access memory (RAM). The apparatus includes a sender for providing a data signal and an initialization status indicator, and a dual port RAM in communication with the sender for receiving the data signal and the initialization status indicator. The dual port RAM has a first memory location for storing the data signal and a second memory location for storing the initialization status indicator of the dual port RAM. The sender performs initialization on the dual port RAM at the beginning of a data transfer cycle which includes a plurality of data transfer from the sender to a receiver. The sender updates the initialization status indicator as the initialization progresses. The receiver of the apparatus is in communication with the dual port RAM. More particularly, the receiver reads the initialization status of the dual port RAM from the second memory location.

Abstract: A method is provided for using a dual port RAM to share data between microprocessors at high speed. By using status indicator flags, microprocessors are able to determine whether the data in memory is current and whether or not it had been utilized.

Abstract: A method is provided for diagnosing a solenoid circuit to determine if the circuit has begun to degrade. By measuring characteristics associated with the electrical waveform, it is determined if the characteristics of a solenoid circuit are different from the previously measured characteristics of the circuit, or of a known functioning circuit.

Abstract: The present invention is a method of fault protection for a microcomputer system. The method determines whether the system returns to a normal or special operating mode if a fault is detected by determining the microprocessor's past history before the fault occurred thereby allowing the microprocessor to get back on track in an appropriate manner.

Abstract: An electronic driver circuit for the open loop control of the energization of a solenoid coil, forming part of an electromagnetic solenoid actuator valve, in response to a control pulse produced by a control circuit and where the predetermined schedules are a function of the inductance and resistance of the coil, the desired peak output voltage from the coil and the desired average holding current through the coil.

Abstract: A method of determining the throttle angle position for an electronic automatic transmission system wherein a controller is programmed to determine the throttle angle position of the throttle in the engine and to detect any failures of the hardware used to determine throttle angle position and upon detecting a failure, providing a default throttle angle value to guarantee satisfactory operation.

Abstract: A method of adaptively idling a transmission in an electronic automatic transmission system putting the transmission to "neutral" when the engine is idling and the brakes are applied.

Abstract: A circuit to provide a regulated voltage output to low priority circuits in a microcomputer based control system from a switchable voltage output of a dual regulator such that the low priority circuits can be de-energized to reduce system current during various modes of system operation.

Abstract: A method wherein a controller is programmed to determine the acceleration of the turbine in the torque converter to control transmission operation during a shift or gear change by counting the number of teeth during a predetermined cycle and dividing that tooth count by the actual time elapsed between the first and last tooth in an automatic transmission.

Abstract: A method of determining the continuity of solenoids in an electronic automatic transmission system wherein a controller is programmed to determine solenoid continuity by checking for the presence of an inductive "OFF" spike which results from an open circuit or a direct short to supply voltage from the solenoid of the solenoid-actuated valves.