8 Bit Asynchronous Multiplier

Overview

This project focused on the design and implementation of an 8-bit asynchronous multiplier optimized for speed, reliability, and manufacturability. The multiplier was engineered to handle input data rates up to 1 MHz, drive a 1 pF load capacitance, and include an asynchronous global clear signal for robust system resets. By incorporating a 16-bit output architecture, the design ensures overflow prevention while maintaining accuracy and efficiency—demonstrating its suitability for real-world, high-performance electronic systems.

Objectives

• Develop a high-speed 8-bit asynchronous multiplier.

• Integrate a global asynchronous clear/reset signal (active-low).

• Ensure robust 16-bit outputs to prevent overflow.

• Optimize for low power consumption and timing accuracy.

• Verify schematic and physical layout with industry-standard design checks (DRC, LVS).

Methodology

1. Schematic Design

• Designed and simulated core building blocks (full adders, flip-flops, multipliers).

• Optimized library cell selection and gate sizing for speed and efficiency.

• Verified functional correctness through waveform simulations.

2. Layout Design

• Implemented the physical layout using Cadence tools with strict 3-metal-layer limits.

• Performed manual optimizations to minimize parasitic effects and improve signal integrity.

• Conducted DRC, LVS, and ERC checks to ensure manufacturability and reliability.

3. Verification & Testing

• Confirmed 1 MHz input handling without timing errors.

• Validated global SET/RESET functionality for robust operation.

• Ensured accurate 16-bit output under all test conditions.

Schematics and Waveforms

1. Full Adder

2. 4 Bit Full Adder

3. 8 Bit Adder

4. D Flip Flop

5. 4 Bit Multiplier

6. 8 Bit Multiplier

Layouts and Testbench

1. Full Adder Layout

2. 4 Bit Full Adder Layout

3. 8 Bit Full Adder Layout

4. 4 Bit Multiplier Layout

5. 8 Bit Multiplier Layout

Final Thoughts

Results

• High Reliability: Stable operation with no glitches during asynchronous reset.

• Performance Accuracy: Successfully processed inputs at 1 MHz without delays.

• Data Integrity: Maintained 16-bit output accuracy with no overflow issues.

• Robust Layout: Optimized routing, minimized parasitics, and confirmed compliance with fabrication rules.

This project challenged my ability to take a digital circuit from schematic to verified physical layout, balancing performance, power, and manufacturability. By combining automated layout generation with manual design optimizations, I ensured that the multiplier met stringent requirements and was ready for real-world application.