Abstract: A control system, as for controlling automotive body functions, is powered by a limited capacity electrical power source and is structured and controlled in a manner to minimize consumption of electrical power. The control system conducts data transactions between a central control station and one or more remote controllers connected therewith, and the central control station includes a provision for electronic signal processing for controlling the data transactions with the remote controllers. A power FET is operatively connected to the power source and to a portion of the control system for selectively connecting or disconnecting power to that control system portion. The system employs a NMOS microprocessor. The portion of the control system from which power may be disconnected will typically include the processor. The level of system activity is monitored and a power-down, or "sleep" control signal is automatically provided if a predetermined condition of inactivity occurs.

Abstract: An electrical power delivery system and method of operation particularly suitable for use in a vehicle is disclosed. A single wire power conductor is connected through remote power switches to a plurality of loads. The power conductor is sized such that its current-carrying capacity is less than the current required to simultaneously operate all the loads connected thereto. Logic means are provided for delivering a control signal to the remote power switches to selectively energize the appropriate loads. The logic means additionally includes means responding to excess current flow through the power conductor to schedule the control signals to prevent simultaneous operation of all the loads thereby limiting current flow through the power conductor to its current-carrying capacity.

Abstract: Arrangement for the input of address data to an integrated circuit (IC) via the same input/output (I/O) terminal pins utilized for the transfer of data is disclosed. The I/O data pins each have an output data latch and an address latch connected to the respective pin and positioned internally of the circuit's interface. A logic level is applied to each of those I/O data pins via a respective external resistor for normally biasing the pin to that logic level. A further I/O pin at the circuit's interface is connected to a common conductor positioned externally of the interface. Diodes are connected between selected ones of the I/O data pins and the common conductor in accordance with a desired address. A level controller responds to a power-on-reset (POR) gating signal to switch the common conductor between a high impedance state and a logic level which effects conduction by the diodes, to enter address data bits. Address latches in the IC store the entered address data bits.

Abstract: A control circuit is provided for selectively determining multiple modes of operation for one or more electrical loads in an automotive accessory system. For a particular load, the circuit includes a switch and a microcomputer signal processing unit. The switch is typically of the momentary-action, dry type which provides a signal only so long as an actuating force is applied. The microcomputer repetitively, at brief intervals determines the presence or absence of such a signal indicative of switch actuation and further is responsive to either brief "momentary" actuation of the switch to effect a primary mode of load control or to a longer "dwell" actuation to effect a secondary mode of load control. The secondary mode of load control includes a characteristic which is determined as a function of the "dwell" duration.

Abstract: An improved debouncer circuit is disclosed for providing debounced, synchronously clocked digital signals from a single-throw switch, as for instance, of the momentary contact type. A signal, variable between two logic levels, is provided by the switch for input to the debouncer circuitry. That input signal is applied as one input to an EXCLUSIVE OR gate, the other input to that gate being fed back from the Q output terminal of an output data latch having complementary Q and Q* output terminals. A signal representing the Q* output terminal of the data latch is connected to the D input of that latch such that a synchronous latch clocking signal appearing at the clock input of the output data latch serves to toggle the states of the Q and Q* output terminals. The signal appearing at either one of the output terminals Q, Q* of the output data latch may be used as the debounced signal provided to other circuitry, depending upon signal polarity needs.

Abstract: An improved serial data protocol/format is provided in a serial multiplex system for use in an automotive vehicle electrical system which is subject to electrical noise. The protocol/format includes successive transactions between a master controller and respective remote controllers each connected to a serial multiplex bus. Each transaction is bidirectional and includes a command message transmitted by the master controller and a reply message normally transmitted by an answering remote controller. Each command message is preceded by a multibit SYNC byte. The command message includes an address byte (for a particular remote controller), a command byte, and an error check such as a cyclic redundance check byte passed on the address and command bytes. The reply message includes the address byte of the replying remote controller, a response byte indicative of its response to the command byte, and an error check such as a cyclic redundancy check byte based on the reply address and response bytes.

Abstract: A serial data communications system, particularly for use in an automotive environment is disclosed in which bidirectional serial data communication is effected between a central control station and one or more remote stations with high integrity. The central control station includes a central controller and at least two multiplex controllers. A serial signal bus is arranged as a loop connected at its opposite ends to respective ones of the two multiplex controllers. A remote multiplex controller, located at each of the remote stations, includes input/output signal ports for input and output, respectively of signals respectively from and to remote input devices and remote load devices. Each remote multiplex controller is parallel "T" connected to the serial bus intermediate its end terminals, has a respective address, and is responsive to a serial communication containing its respective address from the central control station for providing a response to the communication.