CPU cores

Introduction

The SuperH CPU core family comprises 32 and 64-bit CPU cores, CPU core support peripherals and the SuperHyway interconnect technology. Each CPU core family is an implementation of the SuperH Instruction Set as defined below:

Instruction set overview

Renesas has minimized the number of Instruction Set Architecture (ISA) variants in order to provide software developers a consistent platform for targeting kernels, operating systems, middleware and applications. This ensures maximum software reuse and reduces time-to-market for SuperH licensees.

The SuperH ISA comprises the SHcompact and SHmedia ISAs:

• SHcompact 16-bit encoded ISA delivers a complete general purpose instructions and is used in all SH-3, SH-4 and SH-5 processors. The SH4-200 group and SH5-100 group have extended instruction sets that include a set of vector floating point instructions.

• SHmedia 32-bit encoded ISA that exploits the 64-bit datapath capabilities of the SH-5 delivering a rich set of SIMD instructions for audio, speech, graphics and video algorithms. A simple mode switch (on branch) enables programmers to optimize their code using both SHcompact and SHmedia ISAs.

The SuperH ISAs have been designed to deliver:

• Excellent code density through the use of 16-bit encoded instructions. By defining a complete 16-bit ISA (rather than 32-bit or mixed 16 and 32-bit) the SHcompact ISA delivers the best code density. Code density affects the both physical sizes of ROM, RAM and caches and the bandwidth required to enable the memory system to keep the CPU fully loaded.

• Optimized instruction set for multimedia performance. The 32-bit SHmedia delivers highly optimized SIMD instructions for delivering energy efficient performance in embedded systems

• Consistent code base: Software porting costs are one of the largest overheads for licensees and 3rd parties. The SuperH ISA is upward compatible and has not been encumbered with extensions for Java, multimedia or code size reductions. Upward compatibility is maintained across the SuperH family.