The following can be configured for an operating state machine: states, initial state, state transitions, mode, clock polarity.
- States: Up to 8 states can be created and
renamed, if desired.
- Initial state: One of the states creates
can be selected as the initial state in which the state machine macro-cell
resets to following an asynchronous reset.
- State transitions: Users can set the
transition from one state into another to enable a state transition condition
input, with a maximum of 2 transitions into a particular state. The state
transition conditions are inputs from the connection mux and can be configured
to come from any GPI or other macro-cell outputs.
- Mode: The state machine can be selected to
operate in synchronous mode, in which state transition conditions are
synchronously latched in with respect to the clock input, or asynchronous
mode.
- Clock sync: In synchronous mode, this
setting determines whether the state machine is rising edge triggered (sync
disabled), that is state transition inputs and state transitions are latched in
on the rising edge of the clock, or falling edge triggered (sync enabled).
The serial communication interface, if enabled, can be used to read the
current state of an active state machine and reconfigure the state outputs. Any
changes made to the state machine configuration through the serial communication
interface only reflects after the next state transition or a reset event. Thus, to
establish the desired behavior, best practice is to keep the state machine in reset
while reconfiguring the macro-cell.