Date of Graduation


Document Type


Degree Name

Bachelor of Science in Electrical Engineering

Degree Level



Electrical Engineering


Synchronous circuits dominate the semiconductor industry, but asynchronous circuitry is becoming more popular and will continue to do so, as evidenced by the International Technology Roadmap for Semiconductors. Asynchronous circuits, when compared to synchronous circuits, display tolerance to supply voltage and temperature variation. The goal of this project is to demonstrate these two advantages. The project will compare two microcontrollers, a synchronous 8051 and an asynchronous 8031, which will both play a song under various stresses. Note that an 8031 and 8051 are the same, except for the 8051 includes an on-chip instruction memory, whereas the 8031's is off-chip. When the supply voltage is decreased the song on the asynchronous 8031 will slow down, but continue to play. The synchronous 8051 will not slow down and will fail much sooner than the asynchronous 8031, when the supply voltage is decreased. The two microcontrollers will then be introduced to excessive heat. The asynchronous microcontroller, again, will slow down the music, but continue to function, while the synchronous microcontroller will not slow down and fail sooner. The final demonstration will introduce excess cooling. The asynchronous 8051 will speed up the song, while the synchronous 8051 will remain the same. Testing shows that two processors performed are predicted. The synchronous 8051, when the supply voltage was decreased, played the song at a consistent speed before just stopping entirely. The asynchronous 8031 slowed the song down and would resume when the voltage was increased back to its nominal level. Under high temperature variation, the synchronous processor failed entirely. The asynchronous processor slowed down the song when heated. Both processors performed as hypothesized.