Finite State Machine Interface Arbitration for Flash EEPROM

An arbitration structure is introduced as an intermediary component between multiple command sources and the finite state machine. This arbiter manages clock signals and reset signals, selecting which command source controls the FSM at any given time. The arbitration logic evaluates priority levels and current state to determine command acceptance, thereby reducing the complexity burden on the FSM itself while maintaining the ability to handle complex specifications through structured command management.

Multiple clock and reset control functions are merged into a single arbitration structure that centrally manages all command sources. Instead of implementing separate control logic for each internal circuit interface, the arbiter consolidates these functions by maintaining priority registers and control logic that can route commands from any source through a unified interface to the FSM, thereby reducing overall silicon area while preserving multi-circuit interfacing capability.

The command processing system is segmented into distinct functional modules: the arbitration structure that manages command sources, priority registers that determine command selection, and the FSM that executes commands. This segmentation allows testers to independently verify each module's functionality. The arbiter can be tested for correct priority-based selection, priority registers for proper command routing, and the FSM for accurate command execution, thereby improving testability while maintaining simultaneous command processing capability.

The arbitration structure performs preliminary evaluation of incoming commands before they reach the FSM. It assesses whether the FSM is currently busy processing a command and whether the new command has appropriate priority. Commands are buffered or rejected based on this preliminary assessment, preventing command loss while avoiding system overload. This preliminary filtering action maintains high productivity by accepting valid commands while protecting reliability by rejecting commands that would cause conflicts or losses.