Over the last years Transaction Level Modeling has established itself as a valuable strategy to solve system-level design problems prior to the implementation phase. The System-Level Design Working Group of the OCP-IP consortium has contributed SystemC TLM channel packages and methodology guidelines to help the proliferation of this modeling paradigm since 2002. Meanwhile, SystemC in general and TLM in particular have been improved and standardized by Open SystemC Initiative.

The predominant use models for SystemC based Transaction Level Modeling (TLM) are the highly abstract Programmers View (PV) as well as fully cycle-accurate modeling for verification and HDL co-simulation. However, so far no methodology for abstract performance modeling has been established addressing HW/SW partitioning and architectural exploration.

We propose an Architects View (AV) TLM use-case, which is based on revised OCP Transaction Level 2 (TL2) and TL3 APIs. The goal is to allow SoC architects to identify and resolve bottlenecks in the organizations of the SW and HW architectures. Problems to be solved are e.g. the number of processors required, how different pieces of SW and algorithms will access main memory, and what interconnect approach can deliver the required communication bandwidth. The potential of the revised OCP TL2 and TL3 abstractions goes clearly beyond modeling of systems, which will use OCP protocol. In fact, the new TL2 and TL3 APIs enable unified modeling of arbitrary applications and architecture platforms above cycle accurate abstraction.

First, we give an overall picture of ESL design tasks and the corresponding TLM use-cases. The following chapters provide some technical background information on data handling in TLM models and the OSCI TLM standard. The main body of this document is on the OCP based AV design methodology itself, introducing the revised OCP API, demonstrating compliance with OSCI TLM standard, and in particular explaining in detail the Architects View use-case. The last two chapters deal with the widely used Programmers View use-case and the interoperability of PV and AV.