Gecko's CPU Library

IBM PowerPC 401, 403, 405, 440 and 460 processors

Introduction: 1994 (403), 1996 (401), 1998 (405), 1999 (440), 2006 (460)

The PowerPC 400 family is a line of 32-bit embedded RISC-processor cores built using Power Architecture technology. The cores are designed to fit inside specialized applications ranging from System-on-a-chip (SoC) microcontrollers, network appliances, Application-specific integrated circuits (ASICs) and Field-programmable gate arrays (FPGAs) to set-top boxes, storage devices and supercomputers.

AMCC bought assets concerning the 400 family cores from IBM in 2004, and they now market the processors under their own name. IBM continue evolving the cores while supplying design and foundry services around the cores. Several cores are also available for licensing by OEMs from IBM and Synopsys.

PowerPC 403

Introduced in 1994, the PowerPC 403 was the one of the first PowerPC processors, and the first targeted strictly to the embedded market. Compared to the other PowerPC processors of the era (PowerPC 601, PowerPC 603 and PowerPC 604), it was at the very low end, lacking a Memory management unit (MMU) or Floating point unit (FPU), for instance. The core was offered for custom chips and in pre-packaged versions, including versions wih MMU, speeds ranging from 20 to 80MHz.

The PowerPC 403 is used in, among other appliances, thin clients, set-top boxes, RAID-controllers and printers. The first TiVo used a 54MHz PowerPC 403GCX.

AMCC acquired the design of 403 from IBM in 2004, but have chosen not to market it, instead focusing on the 405 and 440 cores.

PowerPC 401

While the 403 was popular, it was also too high performance and too costly for some applications, so in 1996 IBM released a bare bones PowerPC core, called PowerPC 401. It has a single issue, 3 stage pipeline, with no MMU or DMA and only 2KB instrucion and 1KB data L1 caches. The design contained just 85,000 transistors in all and operated at up to 100MHz, drawing only 0.1W or less. Applications using the 401 core range from set-top boxes and telecom switches to printers and fax machines.

PowerPC 405

The PowerPC 405 was released in 1998 and designed for price/performance sensitive low end embedded System-on-a-chip (SoC) designs. It has a 5 stage pipeline, separate 16KB instruction and data L1 caches, a CoreConnect bus, an Auxiliary Processing Unit (APU) interface for expandability and supports speeds exceeding 400MHz. The 405 core adheres to the current Power ISA v.2.03 using the Book III-E specification. Both AMCC and IBM are developing and marketing processors using 405 cores. IBM and Synopsys also offers a fully synthesized cores. IBM has announced plans to make the specifications of the PowerPC 405 core freely available to the academic and research community.

PowerPC 405 based applications includes digital cameras, modems, set-top boxes, cellphones, GPS-devices, printers, fax machines, Network cards, storage devices and service processors for servers. Up to two 405 cores are used in Xilinx Virtex-II and Virtex-4 FPGAs and the future northbridge CPC965 includes an embedded 405 core. In 2004 Hifn bought IBM's PowerNP network processors that uses 405 cores.


The Chinese company Culturecom uses a 405 core for its V-Dragon processor which powers Linux terminals and set-top-boxes. The V-Dragon processor includes the Multilingual Character Generation Engine (MCGE) that processes and generates Chinese characters directly in the CPU.

PowerPC 440

Introduced in 1999, the PowerPC 440 was the first PowerPC core from IBM to include the Book E extension to the PowerPC specification. It also included the CoreConnect bus technology designed to be the interface between the parts inside a PowerPC based System-on-a-chip (SoC) device.

It is a high performance core with separate 32KB instruction and data L1 caches, a 7 stage pipeline, supporting speeds up to 800MHz and L2 cache up to 256KB. The core lacks a floating point unit (FPU) but it has an associated 4 stage FPU that can be included using the APU (Auxiliary Processing Unit) interface. The 440 core adheres to the current Power ISA v.2.03 using the Book III-E specification.

Dual 440 cores are currently used in the processors powering IBM's Blue Gene supercomputer (which as of mid-2005 and 11-2006 ranks number one on the list of the top 500 supercomputers around the world, with a peak performance of over 280 teraFLOPS).

The 440 core is also used in the Cray XT3 and XT4 supercomputers, where its SeaStar and SeaStar2 communication chips closely couples HyperTransport memory interface with routing to other nodes in supercomputer clusters.

Both AMCC and IBM are developing and marketing processors using 440 cores. IBM and Synopsys also offers a fully synthesized cores.

PowerPC 460

Introduced in 2006, the 460 cores are similar to 440 but reaches 1.4GHz, are developed with multi-core applications in mind and have 24 additional Digital signal processing (DSP) instructions. The cores are designed to be low-power but high perfrormance and the 646-H90 is expected to draw only 0.53W at 1GHz. The 460 core adheres to Power ISA v.2.03 using the Book III-E specification.

Source: Wikipedia, the free encyclopedia.