The SLOOP-SMOK Toolkit

SLOOP-SMOK is a toolkit designed to improve the student design experience in an undergraduate machine organization course. The major goals were to improve the relevance of homework assignments to machine organization in general, and to emphasize some fundamental concepts of modern processors not easily addressed previously. SLOOP-SMOK has two components. The SLOOP Machine Organization Kit (SMOK) is a general-purpose software machine organization simulator. The components of a SMOK model are at the level of detail found in typical machine organization texts: ALUs, register files, logic gates, and the like. SMOK provides a graphical interface to construct and debug machine models. The SLOOP is a set of components designed to allow implementation of a modern version of the 6502, the processor used in one of the early Atari game stations. The SLOOP defines a RISC ISA and a set of on-the-fly translations from the original 6502 CISC ISA into SLOOP instructions. Students build SLOOP machines that successfully run most original 6502 games. Extensions to SMOK provide specific help with SLOOP models. In particular, SMOK provides graphical output simulating the game station display, and passes through input events to the SLOOP machine. Additionally, when used with SLOOP, SMOK runs a software 6502 simulator and compares the behavior of the student's SLOOP machine against the simulator on a per-memory-operation basis. This feature simplifies debugging of SLOOP machine organizations by raising an error at the earliest cycle at which the student's machine is known to deviate from correct behavior. SLOOP-SMOK, including downloadable software, documentation, and course assignments, is available at http://www.cs.washington.edu/faculty/zahorjan/SMOK.