DTS

Digital Design Project

📝 Project Overview

Design a 3-bit signed (X) to 3-bit signed (Y) computer, which includes operations: add, subtract, multiply, and XOR. The user can select X, Y, and the operation to compute via physical switches.

• EDA Tool: KiCad 10.0

• Dimensions: 120 x 180 mm

• Layer Count: 2 layers

• Primary Logic: Computes directly through discrete logic gates: AND (CD4081), OR (CD4071), and NOT (74HC04).

• Libraries Used: Standard KiCad library.

📸 Schematics & Layout

---

🛠️ Key Hardware Features

The main functional blocks of the schematic include:

• Power Supply: Uses a 7805 voltage regulator to accept 7 ~ 14 VDC, or just using 5VDC pin to power up the circuit and provide the logic HIGH.

• Adder: A simple 3-bit to 3-bit adder using full adders.

• Two's Complement: Changes the sign of the 3-bit number, utilizing the adder block to also perform subtraction.

• Multiplier: Uses Baugh-Wooley multiplication for multiplying the signed 3-bit numbers.

• Sign Extend: Due to the difference between the output of the multiply operation (6 bits) and all other operations (3 bits), sign-extension logic is added to make all final outputs a uniform 6 bits wide.

---

🔍 Editing the Design

To view or modify the hardware files:

1. Clone this repository to your local machine.

2. Open the main .kicad_pro project file in KiCad 10.0.