RISC-V Technical Specifications
Below is a comprehensive list of all ratified technical publications.
ISA Specifications
These are the current, published versions of the ISA specifications. Prior published versions and the original ratification specifications for included extensions can be found on the RISC-V Technical Specifications Archive page.
Specification name (PDF link) | Version | Published | RISC-V Community | Source Repository |
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The RISC-V Instruction Set Manual Volume I: Unprivileged ISA | 20240411 | May 2024 | ||
The RISC-V Instruction Set Manual Volume II: Privileged Architecture | 20240411 | May 2024 |
Note: Recently ratified extensions, but not yet included in the full specifications, can be found on the RISC-V Ratified Extensions page.
Profiles
These are the current, published versions of the Profiles specifications.
Specification name (PDF link) | Version | Published | Profile(s) | RISC-V Community | Source Repository |
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1.0 | October 2024 | RVA23 | |||
1.0 | October 2024 | RVB23 | |||
1.0 | March 2023 | RVA20, RVI20, RVA22 |
Non-ISA Specifications
These are the current, published versions of the non-ISA specifications. Prior published versions can be found on the RISC-V Technical Specifications Archive page.
Specification (PDF link) | Version | Published | Updated | RISC-V Community | Source Repository |
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Specifies the signals between the RISC-V core and the encoder, compressed branch trace algorithm, and the packet format used to encapsulate the compressed branch trace information to implement processor tracing. | 2.0.3 | June 2022 | April 2024 | ||
Provides the processor-specific application binary interface document for RISC-V. | 1.0 | November 2022 |
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RISC-V Advanced Interrupt Architecture Describes an Advanced Interrupt Architecture for RISC-V systems. | 1.0 | June 2023 |
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RISC-V Capacity and Bandwidth QoS Register Interface Specifies:
| 1.0 | June 2024 |
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Outlines a standard architecture for external debug support on RISC-V platforms. | 0.13.2 | March 2019 |
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RISC-V Functional Fixed Hardware Specification Provides additional system specification for RISC-V systems which use Advanced Configuration and Power Interface (ACPI), specifically for some ACPI object fields of type “Resource Descriptor”. | 1.0.1 | January 2024 | October 2024 | ||
RISC-V IOMMU Architecture Specification Describes an Input-Output Memory Management Unit (IOMMU) that connects direct-memory-access-capable Input/Output (I/O) devices to system memory. | 1.0.1 | June 2023 | September 2024 | ||
RISC-V Platform-Level Interrupt Controller Specification Delineates the operational parameters for a platform-level interrupt controller on RISC-V. | 1.0.0 | February 2023 |
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RISC-V RERI Architecture Specification Augments Reliability, Availability, and Serviceability (RAS) features in the SoC with a standard mechanism for reporting errors by means of a memory-mapped register interface to enable error reporting. Additionally, this specification supports software-initiated error logging, reporting, and testing of RAS handlers. Lastly, this specification provides maximal flexibility to implement error handling and coexists with RAS frameworks defined by other standards such as PCIe and CXL. | 1.0 | May 2024 |
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RISC-V Supervisor Binary Interface Specification Second publication of the RISC-V Supervisor Binary Interface specification. It added a debug console, system suspend, nested acceleration, steal-time accounting, PMU snapshot, and various error codes; relaxed counter width requirements on PMU firmware counters; reserved space for firmware events; and clarified several extensions. | 2.0.0 | January 2024 |
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RISC-V UEFI Protocol Specification Details all new UEFI protocols required only for RISC-V platforms. | 1.0.0 | May 2022 |
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Unformatted Trace & Diagnostic Data Packet Encapsulation for RISC-V Defines an encapsulation format suitable for use with a variety of transport mechanisms, including but not limited to AMBA Advanced Trace Bus (ATB) and Siemens' Messaging Infrastructure. | 1.0 | June 2024 |
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Note: If you do not see a specification in the above table, visit the RISC-V GitHub riscv-non-isa organization to see a complete list of all specifications which have been developed or are presently under development.
Compatibility Test Framework
The RISC-V Architectural Compatibility Test Framework Version 3 (RISCOF version 1.X) is now available.
This framework compares two arbitrary models against each other using a reference signature (one of which should be a reference model) and automatically selects tests according to the model configuration. Because the RISC-V ISA specification allows many architectural implementation choices, a tool (RISCV-CONFIG) has been created to describe implementation configurations. The RISCOF Framework uses RISCV-CONFIG to select and configure tests.
The current test coverage includes RV[32|64]IMCFD_Zb*_zK*_Zmmul_Zicsr_Zifencei (where * means a lot of sub extensions). Work continues to expand extensions supported and configurations covered.
More information can be found in the following locations
Compatibility Test Framework (RISCOF) – GitHub repository, Documentation
Test Framework Configuration Tool (RISCV-CONFIG) - GitHub repository, Documentation
Architecture Compatibility Test suite (ACT) - GitHub repository, Test format specification
RISC-V International