Method and apparatus for providing a state machine operating on a real-time operating system
First Claim
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1. A general purpose computer-based system for implementing a state machine in a computer memory;
- said state machine implementing a process control system for managing processing of inter-task messages between tasks under control of a real-time operating system, the inter-task messages created as a result of hardware events and software events, the state machine comprising;
a first data structure containing one or more first entries, each said one or more first entries including;
a pointer to a second data structure, anda countfield, said one or more first entries each representative of a state, and said count field representative of a count of events valid for said state; and
a said second data structure containing one or more second entries, each said one or more second entries including a Type field, an Event field, a Message ID field, and a state transition routine pointer for providing the address of the state transition routine.
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Abstract
A software state event machine for software based process control systems permits state and events to be unified within a common set of data structures for one or more tasks sharing common state numbers. This method reduces overall memory requirements in systems with extensive states and events among multiple tasks.
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Citations
13 Claims
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1. A general purpose computer-based system for implementing a state machine in a computer memory;
- said state machine implementing a process control system for managing processing of inter-task messages between tasks under control of a real-time operating system, the inter-task messages created as a result of hardware events and software events, the state machine comprising;
a first data structure containing one or more first entries, each said one or more first entries including; a pointer to a second data structure, and a countfield, said one or more first entries each representative of a state, and said count field representative of a count of events valid for said state; and a said second data structure containing one or more second entries, each said one or more second entries including a Type field, an Event field, a Message ID field, and a state transition routine pointer for providing the address of the state transition routine. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- said state machine implementing a process control system for managing processing of inter-task messages between tasks under control of a real-time operating system, the inter-task messages created as a result of hardware events and software events, the state machine comprising;
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8. A state machine method for use in a process control system for managing processing of inter-task messages between tasks under control of a real-time operating system(RTOS), the inter-task messages created as a result of hardware events and software events, the method comprising the steps of:
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dequeuing an inter-task message; checking said inter-task message for a known Event Control Block entry; getting a pointer to a State Pointer table; checking State Pointer table entry for a NULL pointer; accessing a Type Event table using a second pointer; comparing a Type Event table Message ID field to an Identity field of said inter-task message; comparing an Type Event table Event field to a second Event field of said inter-task message; and comparing a Type Event table Type field to a second Type field of an inter-task message. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification