🔀 Choosing Between `~` and `!`

Best Practice Use ~ for bitwise signal inversion (gate-level intent).
Use ! for logical truth evaluation (Boolean intent).

🔁 ~ Bitwise NOT

• Inverts each bit of the input.
• Output is same width as input.
• Synthesizes to inverter gates.
• ✅ Use when flipping signal polarity or manipulating data paths.

Examples:

~4'b0101 → 4'b1010
~1'b0    → 1'b1

❗ ! Logical NOT

• Returns 1 if the entire value is zero, else 0.
• Output is always 1-bit.
• Synthesizes to zero comparator.
• ✅ Use in control logic, conditionals, or flag checks.

Examples:

!4'b0000 → 1'b1
!4'b0101 → 1'b0

🧩 Rule of Thumb