Design Organization and Summary

The requirements for the design where defined by Prosser and Winkel and the PD-P8 system manual. This included all of the instruction and register requirements. Prosser and Winkel discussed most of the design issues, so a lot of our design is based off of their work.

The main goal in designing the PD-PP was to keep the design flexible to allow changes to be made and features added as the implementation proceeded. This let us add more features given time constraints and ideas which we had during the two months spent building the PD-PP

The second goal was to keep the design easily debug-able. This included keeping the internal state as minimal as possible while adding features that made testing easier.

As a result of these goals we decided to have the following features which are differences from the Prosser and Winkel design.

• Loading and displaying of all datapath registers. Being able to examine all of the registers is critical for debugging.
• Automatic displaying of internal registers. To further aid in debugging, being able to monitor datapath registers while a program is running can greatly simplify testing.
• PC Parallel Port Interface. This feature, although added quite a bit of logic to the board, made downloading programs much simpler. This feature was a direct result of the first goal since we left one of the switches unused in our original design and as it turned out, proved useful with the introduction of the parallel port.

• Front Panel and Display Leds
• Control and Datapath Design