Logic system and method employing multiple configurable logic blocks and capable of implementing a state machine using a minimum amount of configurable logic

摘要

A logic system is presented including multiple configurable logic blocks (CLBs) implementing a state machine having multiple states, each state being associated with one or more logic functions and one or more possible next states. Each CLB includes programmable logic circuitry, and is configurable to implement the logic functions required in any given state. A complex state machine may be implemented using only 1+s CLBs, where s is the maximum number of next states of any state, thereby using a minimum amount of configurable logic. The logic system also includes a memory unit, a control unit coupled to the memory unit and to each of the CLBs, and an interface unit coupled to the control unit and to each of the CLBs. The memory unit stores configuration data required to configure the CLBs and state transition information. The control unit generates and stores current state information. Following programming, a single "active" CLB implements the logic functions required in the current state. The remaining CLBs are "inactive". While in the current state, the control unit uses state transition information from the memory unit and current state information to determine the possible next states. The control unit then retrieves configuration data from the memory unit corresponding to each of the possible next states, and programs one inactive CLB for each possible next state. The interface unit routes input signals to, and output signals from, the active CLB in response to a control signal from the control unit.