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The Wimp51: A Simple Processor And Visualization Tool To Introduce Undergraduates To Computer Organization

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2002 Annual Conference


Montreal, Canada

Publication Date

June 16, 2002

Start Date

June 16, 2002

End Date

June 19, 2002



Conference Session

Real-Time and Embedded Systems Education

Page Count


Page Numbers

7.1200.1 - 7.1200.7



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Paper Authors

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Hardy Pottinger

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Daryl Beetner

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NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Main Menu Session ____

The WIMP51: A Simple Processor and Visualization Tool to Introduce Undergraduates to Computer Organization

David Sullins, Hardy Pottinger, Daryl Beetner University of Missouri – Rolla

I. Introduction

The University of Missouri – Rolla offers a Junior-level lecture and laboratory course in hardware/software co-design1. The course focuses on the 8051 family of microcontrollers. Many students who take this course have no prior experience with processor architecture, so a short introduction to some basic concepts of computer organization is given in the first few weeks of the course.

In the past, the computer architecture portion of the course was taught using the Gnome processor, described in Van den Bout’s Practical Xilinx Designers Lab Book2. The Gnome is a four-bit processor with eight-bit instructions described in VHDL and targeted for the Xilinx 4k series FPGA. While the Gnome is at an appropriate level of complexity for the course, it is quite different from the 8051 microcontroller. Past course evaluations indicate that many students feel their time was wasted learning the Gnome instruction set, only to be told to forget the Gnome instructions and learn a new instruction set three weeks into the course. Still, the Gnome is useful in the classroom, as the 8051 microcontroller is much too complex for a short introduction to computer architecture.

To resolve these problems a replacement processor based on the 8051 was designed. Called the WIMP51, it is a simple binary-compatible subset of the 8051, lacking internal memory, interrupts, peripherals, and many of the 8051 instructions. The WIMP51 was implemented in synthesizable VHDL and an interactive graphical simulator was developed for use in lab.

II. WIMP51 Design

The WIMP51 is a classic von Neumann processor. Every instruction lasts three clock cycles, one clock cycle for each phase: Fetch, Decode, and Execute. All WIMP51 instructions are assembly language and machine language compatible with the Intel 8051. Table 1 shows t he WIMP51 instruction set.

Proceedings of the 2002 American Society for Engineering Education Annual Conference & Exposition Copyright © 2002, American Society for Engineering Education

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Pottinger, H., & Beetner, D. (2002, June), The Wimp51: A Simple Processor And Visualization Tool To Introduce Undergraduates To Computer Organization Paper presented at 2002 Annual Conference, Montreal, Canada. 10.18260/1-2--10788

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