A Gentle Introduction To Addressing Modes In A First Course In Computer Organization

This paper describes the reform of a sophomore-level course in computer organization for the Computer Science BS curriculum at The University of Texas at El Paso, where Java and integrated IDEs have been adopted as the first and primary language and development environments. This effort was motivated by faculty observations and industry feedback indicating that upper-division students and graduates were failing to achieve mastery of nongarbage-collected, strictly imperative languages, such as C. The similarity of C variable semantics to the underlying machine model enables simultaneous mastery of both C and assembly language programming and exposes implementation details that are difficult to teach independently, such as subroutine linkage and management of stack frames. An online lab manual has been developed for this course that is freely available for extension or use by other institutions. Our previous papers reported on pedagogical techniques for facilitating student understanding of the relationships between high-level language constructs, such as algebraic expression syntax, block-structured control-flow structures, and composite data types, along with their implementations in machine code. While this integrated approach to introducing control-flow structures has been successful, many students have been confused by the large number of different addressing modes. The present paper describes further extensions of this integrated Cand-assembly language pedagogical approach in which addressing modes are introduced incrementally as solutions to pragmatically motivated problems. Initial results, as measured by quizzes and in-class exercises, are highly encouraging.