S5 series


The SiFive S54 Standard Core is a 64-bit embedded processor that is fully-compliant with the RISC-V ISA. It adds support for the F and D standard extensions, which provide the S54 with double-precision floating-point capabilities.

The S54 is ideal for demanding applications such as avionics, signal processing, and industrial automation.

Key Features
  • Fully compliant with the RISC-V ISA specification
  • RV64IMAFDC Support
    • RV64I – 64-bit RISC-V with 32 integer registers
    • Integer Multiplication and Division (M) support
    • Atomic (A) extension for high-performance, portable software
    • F and D extension for hardware double-precision floating-point
    • Compressed (C) extension for better code density
  • Machine and User Mode Support
  • In-order, 5-6 stage variable pipeline
  • Advanced Memory Subsystem
    • 16KB, 2-way Instruction Cache
    • Instruction Tightly Integrated Memory (ITIM) option
    • Up to 64KB Data Tightly Integrated Memory (DTIM) support
  • Support for up to 40 physical address bits
  • Efficient and Flexible Interrupts
    • Local interrupts w/ vectored addresses — up to 16
    • Platform Level Interrupt Controller (PLIC) — 255 interrupts w/ 7 priority levels
    • RISC-V Core Local Interruptor (CLINT) — 1 timer, 1 SW
  • 8-Region Physical Memory Protection (PMP)
  • High performance TileLink Interface
  • 2.87/1.70 DMIPS/MHz (Best Effort/Legal)
  • 3.01 CoreMark/MHz

Power, Performance
and Area

28nm HPC
55nm LP
Core-Only Areaa
0.11 mm²
0.312 mm²
Core Complex Areab
0.174 mm²
0.49 mm²
870 MHz (worst)
340 MHz (worst)
Core Complex Powerc
7.48 mW
19.2 mW

Note: Area and power numbers do not include RAMs. Area numbers are from 200MHz Post-Route at worst setup corner

a. Core only includes the core pipeline, and L1 memory interfaces

b. Core Complex includes the Core plus PLIC w/255 irq and 7 priority levels, Debug w/ 4 hw breakpoints, CLINT, internal bus and AXI ports

c. Dhyrstone @ 200MHz TT Vnom 25C

Compare to Cortex-R5F

S5 Series
Up to 8 Cores (fully-coherent)
Up to 2 Cores (non-coherent)
Interrupt Controller
Included; pre-integrated
Licensed separately; requires integration
L2 Cache Controller
Included (optional); pre-integrated
Licensed separately; requires integration

Development Kit

Dev Kit Deliverables

  • RTL Evaluation
  • Test Bench RTL
  • Software Development Kit
  • FPGA Bitstream
  • Documentation
Series Overview

S5 Series

The S5 Series offers 64‑bit RISC‑V performance with 32‑bit power and area. The S5 core has a 5-6 stage pipeline, offering a great balance between performance and efficiency.

S5 Series

Key Features

  • Up to 8 coherent S5 Cores and optional L2 Cache Controller
  • Configurable core performance
  • Double precision Floating Point Unit
  • Level 1 Memory System and ECC
  • Number, type, and width of bus interfaces


  • Consumer Electronics
  • Motor Control
  • Industrial Automation
  • Storage
  • High-performance embedded

All Standard

Standard Cores
ARM Comparison
E2 Series
M0, M0+, M3, M4, M23, M33
E3 Series
R4, R5
E7 Series
M7, R7, R8
S2 Series
S5 Series
R4, R5
S7 Series
M7, R7, R8
U5 Series
A5, A7, A35, A53
U7 Series
Core Evaluation

From idea
to reality.

Ready to see your code in action? The S54 Development Kit enables free evaluation of SiFive RISC-V Core IP.


Evaluation RTL

  • Full-Functional, synthesizable Verilog RTL
  • Run it in your own simulator
  • Simple, no-cost evaluation license
Start S54 Free Trial

FPGA Bitstream

  • Fully-functional SiFive RISC-V Core Complex with system peripherals
  • High Performance - 32.5 MHz emulation
  • Upload your own programs using the Freedom E SDK

Compatible with the Arty A7-100T FPGA Development Board: