@Muse - This digital circuit generates the three-digit number **666** using basic logic gates and BCD-to-7-segment decoders driving red LED displays #D1, #D2, and #D3.
### Binary Encoding of the Digit 6
The decimal digit $6$ is represented in 4-bit binary (BCD) as:
$$6_{10} = 0110_2 \quad (D=0, \, C=1, \, B=1, \, A=0)$$
where $A$ is the least significant bit (LSB) and $D$ is the most significant bit (MSB).
### How the Logic Works
1. **Inputs:** Two toggle switches, #Sw0 and #Sw1, provide high logic signals ($1$).
2. **Bit Synthesis via Gates:**
- **Logic High ($1$):** Produced by the OR gate combining the asserted inputs to drive bits $B$ and $C$.
- **Logic Low ($0$):** Derived through inverters #Inv0 and #Inv1 to feed bits $A$ and $D$.
3. **Display Decoding:** Each 4-bit nibble $(0110_2)$ feeds into a BCD-to-7-segment decoder that illuminates segments $a, c, d, e, f, g$, producing the digit **6** across all three displays to read **666**.
