Expandable, mobile, modular microcomputer system for an off-road vehicle

An expandable, mobile, field reprogrammable modular microcomputer system for controlling a powershift transmission of an off-road vehicle, said system comprising:

• controller means for receiving at least one input from an external information generating device and for generating at least one pulse-width modulated output control signal and at least one on/off output control signal;
• interface means coupled to said controller means for enabling bi-directional communication between said controller means and a reprogramming device such that said reprogramming device can be utilized to reprogram said controller means while said off-road vehicle is still at a work site and without removing said controller means from said off-road vehicle;
• watchdog means for monitoring operation of said controller means and for generating a reset signal operable to reset said controller means when said watchdog means detects improper operation of said controller means;
• means for independently powering said watchdog means;
• means for monitoring said watchdog means and overriding operation of said watchdog means when said independent power means powering said watchdog means fails to supply a predetermined minimum power to said watchdog means;
• at least one first switch means responsive to said pulse-width modulated control signal of said controller means for generating a pulse-width modulated drive signal;
• and
• at least one second switch means responsive to said on/off control signal of said controller means for generating an on/off drive signal.

An expandable, mobile, field reprogrammable modular microcomputer system for controlling a powershift transmission of a heavy-duty, off-road vehicle, said system comprising:

• a plurality of current sourcing digital inputs;
• a plurality of current sinking analog inputs;
• a plurality of current sinking digital inputs;
• a microcomputer responsive to said current sourcing digital inputs, said current sinking digital inputs, and said current sourcing analog inputs for generating a first plurality of independent, pulse-width modulated control signals and a second plurality of independent, on/off control signals;
• circuit means for permitting and managing communication between said microcomputer and at least one additional controller system modularly and removably interfaced to said microcomputer;
• a power supply;
• a first voltage regulator responsive to said power supply for generating a first regulated voltage, said first regulated voltage being operable to power said microcomputer;
• a second voltage regulator responsive to said power supply for generating a second regulated voltage, said second regulated voltage being operable to supply a current to said current sourcing digital inputs;
• a watchdog circuit for monitoring operation of said microcomputer and generating a reset signal for resetting said microcomputer when said watchdog detects a condition of spurious operation of said microcomputer, and for generating a back-up voltage enabling signal when a malfunction of the microcomputer is detected;
• a back-up voltage regulator circuit responsive to said back-up voltage enabling signal and at least one of said analog current sinking inputs for generating an auxiliary, pulse-width modulated control signal to control at least one of said first switching circuits;
• a bi-directional serial communications interface circuit for enabling said microcomputer to communicate with a reprogramming device for reprogramming said microcomputer while said off-road vehicle is at a field work site;
• and
• a multiplexer responsive to a plurality of said current sourcing analog inputs and said microcomputer for selectively coupling said plurality of current sourcing analog inputs with said microcomputer.