riscv

History

Andrew Waterman 2d1d7266f5 Fix RV64 badaddr value on instruction faults with large addresses We were relying on ALU passthrough for this, but failed to override the ALU dw argument, so bits above 31 could be discarded.		2016-08-15 23:09:09 -07:00
..
src/main/scala	Fix RV64 badaddr value on instruction faults with large addresses	2016-08-15 23:09:09 -07:00
.gitignore	add .gitignore	2014-08-18 19:27:50 -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
build.sbt	Add ability to generate libraryDependency on cde.	2015-10-22 11:37:20 -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