HDL1049: Deadlock FSM states should be reviewed
Summary
| Reliability | Security | Maintainability | Code attribute | Effort to fix | Tags |
|---|---|---|---|---|---|
| HIGH | - | - | Intentionality | Logical | 20min | synthesis, bug-finder, fsm, linty-ultra |
Description
This rule detects finite state machines (FSM) defining deadlock states. A deadlock state (also called a lockup state) in an FSM is a state that, once entered, cannot be left. No combination of inputs produces a transition to a different state. The machine stays there forever (unless reset).
Note that this rule is only checked for FSM that define a reset/initial state.
Deadlock states are a sign of a design error, and they can lead to unexpected behavior in the circuit.
Parameters
No parameters.