SPANKy summary

SPANKy!

Brought to you by group GAMMA:
Victoria Smith (vics@rice.edu)
Mara Prandi-Abrams (mabrams@rice.edu)
Dennis Geels (geels@rice.edu)
Overview - Functional Specifications - ISA - Controller - Design and Layout - Performance Analysis - Summary

423 Final Report

Project Summary and References

The design for our microprocessor was partially influenced by our 327 project, but was mostly a straightforward implementation of a RISC register to register architecture. We also got ideas for the layout of our barrel shifter from our textbook by Weste.

The work was very equitably shared amoung our group members. Dennis and Vicki worked on the initial design, and Dennis did almost all subsequent refinements of that design. The lower-level subcells were divided as follows:

Mara put together the instruction register/decoder block; Dennis put together the pc loop. Vicki put together the ALU, the register file, and did most of the routing. Mara and Vicki did the bulk of the circuit debugging. Dennis wrote and assembled the multiplication process that we used to test the entire block. All three of us tested and debugged spanky at the highest level; everyone tested their own blocks extensively. Mara did the bulk of the timing analysis and presentation preparation. Dennis maintained the webpage.

Comments and Suggestions

While the gamma group very much enjoyed this project, we feel that we would have benefitted from better CAD tools and/or better documentation of existing tools. While the paperwork was voluminous, it was poorly indexed and often out of date. Many of the tools could have been fully explained in one page. Also spice really needs to be introduced earlier in the course so that groups do not have to make last-minute basic layout changes that may affect the entire hierarchy. We also think that the groups should have been encouraged to draw their own n-wells so as to avoid the drc errors when the final design is flattened.