The SuperH (or SH) is brandname of a certain microcontroller and microprocessor architecture. The SuperH is fundamentally a 32-bit load/store RISC architecture found in a large number of embedded systems.

The SuperH processor core family was first developed by Hitachi in the early 90's. Many microcontrollers and microprocessors were based on this architecture. Maybe, most famous is the SH7709 device used in the HP Jornada PDA running Windows CE.

Hitachi was developing a complete set of instruction set upward compatible CPU cores. Originally, the SH-1 and the SH-2 were used in the Sega Saturn and then later in many other microcontrollers used in many other embedded applications. These cores use a 16-bit instruction set, though register length and data paths are 32-bit, which gave it an excellent code density. At the time, memory was very expensive.

A few years later, the SH-3 core was added to this family of CPU cores extending the original cores mainly by another interrupt concept, a memory management unit (MMU) and a modified cache concept. The SH-3 core also got a DSP extension, then called SH-3-DSP core. With extended data paths for efficient DSP processing, special accumulators and a dedicated MAC-type DSP engine, this core was unifying the DSP and the RISC processor world. A derivative was also used with the original SH-2 core, then called SH-DSP.

For the Sega Dreamcast, Hitachi was then developing the SH-4 architecture. This was a massive extension of the previous cores. Superscalar (2-way) instruction execution and a parallel vector floating point unit were the highlights of this architecture. This CPU core was then also used in many chipsets for embedded applications requiring a very high performance. SH-4 based standard chips were roughly introduced around 1998.

A bit later, Hitachi and ST Microelectronics formed the IP company SuperH, Inc which was going to license the SH-4 core to other companies and was developing the SH-5 architecture. The first move of SuperH into the 64-bit area. SuperH, Inc. sold the IP of these CPU cores.

The SH-5 design added a SIMD instruction set called SHmedia and also supports the SHcompact instruction set, equivalent to the user-mode parts of the SH-4 instruction set. The implementation is comparable to the Thumb Instruction Set of ARM.

After that, the evolution of the SuperH architecture still continued. The latest evolutionary step happened around 2003 where the cores from SH-2 up to SH-4 were getting unified into a superscalar SH-X core which forms a kind of instruction set superset of the previous architectures.

Today, the SuperH CPU cores, architecture and products are with Renesas Technology, a merger of the Hitachi and Mitsubishi semiconductor groups. See further details under Renesas.

The family of SuperH CPU cores include:

• SH-1 - used in microcontrollers for deeply embedded applications (CD-ROM drives, major appliances, etc)
• SH-2 - used in microcontrollers with higher performance requirements, also used in automotive such as engine control units or in networking applications
• SH-DSP - initially developed for the mobile phone market, used later in many consumer applications requiring DSP performance for JPEG compression etc
• SH-3 - used for mobile and handheld applications, strong in Windows CE applications and market for many years in the car navigation market
• SH-3-DSP - used mainly in multimedia terminals and networking applications, also in printers and fax machines
• SH-4 - used whenever high performance is required such as car multimedia terminals, video game consoles, or set-top boxes
• SH-5 - used in high-end multimedia applications
• SH-X - mainstream core used in various flavours (with/without DSP or FPU unit) in engine control unit, car multimedia equipment, set-top boxes or mobile phones

The SuperH cores are widely supported by many RTOS and tool vendors all over the world.

Distinctions

• Scalability
• Cost efficient
• Optimised for embedded applications
• High performance

External links

Products, Cores, Tools, Manuals, Information

• http://www.renesas.com/

• http://www.kpitgnutools.com, Official free SH GNU Toolchain with Support
• http://www.linux-sh.org/, http://linuxsh.sourceforge.net/
• http://www.sh-linux.org/ gcc toolchain
• http://LinuxDC.sourceforge.net/ Linux on Dreamcast
• http://www.shlinux.com/ MPC Data SHLinux support
• http://www.STLinux.com/

Linux Distributions for SuperH

• http://www.jlime.com/ (Jornada Linux Mobility Edition) has working distribution for HP Jornada 620LX/660LX/680/690 handhelds (as well as ARM architecture based), JLime is probobly the largest SuperH distribution.

NetBSD on SuperH

• http://www.netbsd.org/Ports/sh3/
• http://www.netbsd.org/Ports/sh5/

Microprocessors

SuperH | SuperH | SuperH | SuperH | SuperH