SuperH

From Sega Retro

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The SuperH (or SH) is a family of microprocessors, originally developed by Hitachi during the 1990s as the successor to the H8 family, and now supported by Renesas. They were notable for their time as being capable, yet relatively cheap units with low power consumption.

The SuperH family was introduced in 1992.[1] It was the first CPU to support an efficient Thumb-like instruction set (with single-cycle instructions) and hardware support for multiply–accumulate (MAC) operations (two cycles per MAC operation). Between 1994 and 1996, 35.1 million SuperH devices were shipped worldwide, with a 32% share of the microprocessor market in 1996.[2]

Sega has used SuperH chips as the central processing unit for a number of video game consoles and arcade machines:

  • SH-1: Used on the Sega Saturn console to control the CD-drive and to check copy protection on game discs.
  • SH-2: The main processor behind both the Sega 32X and Sega Saturn. Both consoles used two SH-2 processors in parallel.
  • SH-4: Used in the Sega Dreamcast console and arcade systems such as the NAOMI, Hikaru and NAOMI 2. It was particularly suited for 3D graphics, capable of calculating 1.4 GFLOPS and more than 10 million lit polygons per second.[3] The SH-4 was introduced in 1997.[2] It was the first CPU with 4D vector instructions, nearly a decade before the PowerPC VMX128 (2005) and Intel SSE4 (2006).

SH-3 and SH-5 chips also belong to the family, but were never utilised by Sega. Towards the early 2000s, the family had perhaps out-lived its potential in video gaming, however the technology continues to see widespread use in other forms of electronics. For example, the SuperH instruction set was adapted for the ARM architecture's Thumb instruction set.

References