Moving Beyond VHDL in Introductory Computer Architecture Courses: An Exploration of MyHDL as a Modern Alternative

In this Innovative Practice Full Paper we analyze the impact of using modern Hardware Description Languages (HDL) on introductory computer architecture courses. More specifically, we study whether the choice of HDL influences students' ability to i) draw a diagram from an HDL code; and ii) describe a circuit shown in diagram form using an HDL. Using HDL in digital logic courses has been explored in the past by many other authors. However, few studies have examined how this affects students' learning experiences. In both our experience and previous literature, traditional HDLs such as VHDL are difficult to test and debug, resulting in students writing solutions that do not work and students (and faculty) struggling to identify the problem. Although more modern and easier-to-use HDLs, such as MyHDL, have emerged as proven alternatives to VHDL in the last decade, their use in education has not yet been explored. In particular, MyHDL provides several advantages compared to VHDL: (i) it provides a higher level of abstraction; (ii) it includes a built-in simulation feature that simplifies the process of debugging and verifying hardware; (iii) it uses Python, allowing students to use familiar editors and coding environments; and (iv) it generates VHDL code that can be synthesized to FPGAs. Through this study, we provide insights into the impact of different HDL languages on some aspects of a computer architecture course. We conducted an A/B test comparing the use of two HDL languages, MyHDL and VHDL, over the course of a semester in two similar undergraduate disciplines. MyHDL was used in the second semester of a computer science course (N =26), while VHDL was used in a third-semester computer engineering course (N=34). For both groups, this was their first experience with computer architecture, and the courses shared the same materials, assignments, group work, and schedules. Both courses are based on the Nand To Tetris book [1]. Our findings reveal no significant difference between students who used VHDL and those who utilized MyHDL. Both groups, with comparable foundational knowledge in digital systems and similar misconceptions, demonstrated equivalent performance in describing hardware from HDL, analyzing the hardware's functionality, and creating simple hardware from a given problem. Based on our results, we conclude that employing MyHDL as an HDL in introductory computer architecture courses could be a viable alternative to traditional HDL languages. MyHDL not only delivers similar student performance outcomes but also provides easier-to-use tools that are closer to what students are accustomed to.