The Designer's Guide to VHDL, 3rd Edition

Chapter 22. Case Study: System Design Using the Gumnut Core

In this case study we develop a series of models for the Gumnut 8-bit microcontroller core, described in Digital Design: An Embedded Systems Approach Using VHDL [2]. We first develop a behavioral model and verify it using a test bench consisting of instrumentation to monitor instruction execution. Next, we refine the model to the synthesizable register-transfer level. We verify this version in a test bench that compares its outputs with those of the behavioral version. Finally, we develop a system model of a digital alarm clock that uses the Gumnut as an embedded soft core, and synthesize the system for implementation in an FPGA target.

Overview of the Gumnut

The Gumnut is an 8-bit processor ...