riscv/rocket-chip
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Andrew Waterman 5aa8ef1855 Remove invalidation support from BTB 
Validating the target PC in the pipeline is cheaper than maintaining
the valid bits and control logic to guarantee the BTB won't ever
mispredict branch targets.
2016-07-02 14:27:29 -07:00
..
src/main/scala Remove invalidation support from BTB 2016-07-02 14:27:29 -07:00
.gitignore add .gitignore 2014-08-18 19:27:50 -07:00
build.sbt Add ability to generate libraryDependency on cde. 2015-10-22 11:37:20 -07:00
LICENSE add LICENSE 2014-09-12 15:36:42 -07:00
README.md update README 2014-09-17 11:23:25 -07:00

README.md

Rocket Core

Rocket is a 6-stage single-issue in-order pipeline that executes the 64-bit scalar RISC-V ISA. Rocket implements an MMU that supports page-based virtual memory and is able to boot modern operating systems such as Linux. Rocket also has an optional IEEE 754-2008-compliant FPU, which implements both single- and double-precision floating-point operations, including fused multiply-add.

This repository is not intended to be a self-running repository. To instantiate a Rocket core, please use the Rocket chip generator found in the rocket-chip git repository.

The following table compares a 32-bit ARM Cortex-A5 core to a 64-bit RISC-V Rocket core built in the same TSMC process (40GPLUS). Fourth column is the ratio of RISC-V Rocket to ARM Cortex-A5. Both use single-instruction-issue, in-order pipelines, yet the RISC-V core is faster, smaller, and uses less power.

ISA/Implementation ARM Cortex-A5 RISC-V Rocket R/A
ISA Register Width 32 bits 64 bits 2
Frequency >1 GHz >1 GHz 1
Dhrystone Performance 1.57 DMIPS/MHz 1.72 DMIPS/MHz 1.1
Area excluding caches 0.27 mm2 0.14 mm2 0.5
Area with 16KB caches 0.53 mm2 0.39 mm2 0.7
Area Efficiency 2.96 DMIPS/MHz/mm2 4.41 DMIPS/MHz/mm2 1.5
Dynamic Power <0.08 mW/MHz 0.034 mW/MHz >= 0.4