Incas: a cycle accurate model of UltraSPARC

This paper describes a cycle accurate model of the UltraSPARC processor. The model is written in C++, and is built on top of a powerful programming framework with a built-in message-passing mechanism and a timing discipline for simulating concurrent modules. The goal was to help verify the processor by cross checking the RTL model at run time, as well as to provide accurate performance estimates. Because of Incas' much faster execution rate than the RTL, it was also used to model the UItraSPARC module in RTL simulations of the full system, for compiler and library tuning, and for diagnostics development.