IBM, Sony pull the covers off the Cell chip

Posted on 26 Aug 2005 at 11:12

IBM and Sony have released the first details about the inner workings of the Cell Broadband Engine Architecture (CBEA) otherwise known as the Cell chip. The details are to allow programmers and developers to begin work on developing a new generation of software and games for the chip.

The three companies involved in the development of the CBEA: IBM, Sony and Toshiba, have high hopes for the future of the design and expects this to be the first member of a new generation of processors. Although developed specifically for game consoles and similarly media-rich consumer-electronics devices, a much wider use of the architecture is envisioned.

The Cell is based around 64-bit Power Architecture technology, but with a distinctive design tuned for distributed processing and media-rich applications. The first commercial appearance of the Cell is likely to be in the forthcoming Playstation 3 due next year.

The design itself is of a single-chip multiprocessor consisting of one or more Power Processor Elements (PPEs) and multiple high-performance SIMD (Single Instruction Multiple Data) Synergistic Processor Elements (SPEs). SIMD is a technique used in parallel processing whereby a single instruction is distributed around the system and used on different data.

Each SPE is an independent processor running its own application programs, although they share coherent memory. IBM also says that the Cell supports a number of Direct Memory Access commands for efficient communications between all Cell processing elements.

The PPE will access main storage (the effective-address space that includes main memory) with load and store instructions that go between a private register file and main storage (which may be cached). On the other hand, the SPEs access main storage with DMA commands that go between main storage and local memory used to store both instructions and data. SPE fetch, load and store instructions access this local store rather than shared main storage.

More details of the Cell processor can be found at the IBM web site.

Author: Steve Malone