05_ESDM_FSMPatterns.md

IV. FSM Patterns

FSM Patterns

• Design patterns: reusable templates which appear often in applications

• Patterns

  • Operating on signal transitions
  • Debounce (one-sided, two-sided)

Operating on signal transitions

• For boolean signals/conditions

• Use when information is in the signals' fronts (edge / transition) rather than in its values

• Solution: detect signal transitions

  • rising edge
  • falling edge
  • both

Detect rising edge

• Draw here: detect rising edge

Detect falling edge

• Draw here: detect falling edge

Detect any edge

• Draw here: detect any edge

Debouncing

• For boolean signals/conditions

• Bouncing: real signals look like this:

{width=40%}

• Use debouncing to avoid spurious transitions

Debouncing rising edge

• Draw here: debounce rising edge

Debouncing falling edge

• Draw here: debounce falling edge

Debouncing both edges

• Draw here: debounce both edges