The Roving Robot Microcontroller (RVRBOT)

Elec 422/423 - VLSI Design

Dr. Joseph Cavallaro



Group Members


Project Overview

Last semester we completed algorithm design, logic design, and circuit layout for a microcontroller for a robot designed to locate a transmitter broadcasting at a given signal strength. To find the source, the microcontroller samples the signal and makes calculations based on the intensity of the signal and the robot's location to determine the direction of the transmitter. For more details, view the functional description, view an example of the robot's search pattern, and look at some simulation code written for algorithm testing.


Chip Design and Test


Chip Fabrication and Test

The design was fabricated by the MOSIS foundation.

We tested the completed chips we received from MOSIS. Testing was done using the OMNILAB system, which interfaces with an IBM compatible personal computer. Our major functionality tests included 5 test vectors which tested all of the possible states and state transitions in the algorithm control unit, tested all ALU operations, and tested to make sure the robot never wandered beyond the boundaries of the world it was "exploring" (final_r7.cmd, north.cmd, south.cmd, east.cmd, and west.cmd). These vectors correspond to the previous IRSIM results.

According to our testing, 3 of the 4 chips we were issued are completely functional. The last chip is functional in almost all aspects, but one bit of one of the boundaries is stuck at 1. On review of the design of the latch storing this data, there do not appear to be any reasons for this failure. Additionally, since 127 other latches across the chips are operating correctly, we concluded that this was most likely a fabrication error.

Additionally, our chips operated correctly at up to 8.52 MHz, the fastest speed at which a non-overlapping two-phase clock can reliably be tested.

For more information, see the report we submitted to MOSIS for review.



-- Michael Hunt (mch@rice.edu)
-- Jessica L Pistole (jessica@rice.edu)
-- Tino Tran (tinotran@rice.edu)