SCR1 Microcontroller Core

SCR1 is an open-source and silicon-proven RISC-V-compatible, 32-bit, entry-level, MCU-class core. It targets general-purpose, deeply embedded applications and control systems.

SCR1 supports RISC-V standard "I" Integer, "E" Reduced Base Integer, "M" Integer Multiplication and Division, and "C" 16-bit Compressed extensions. SCR1 is equipped with an in-order 4-stage pipeline, a TCM unit, an IPIC unit for efficient interrupt processing, as well as industry-standard AXI4, AHB-Lite, and JTAG/cJTAG interfaces for flexibility and compatibility.

The core is open-sourced under the permissive SHL license, comes with pre-configured software tools, and is ready out-of-the-box for commercial and educational purposes.

SCR1 Microcontroller Core


  • Internet of things
  • Smart cards
  • Control systems
  • Sensors
  • Smart home
  • Education programs

SCR1 Key Features

ISA RV32I/E[MC], Integer Multiplication and Division [M], Compressed Instructions [C] — optional
Pipeline 2-4 stages
Memory Subsystem
Tightly-Coupled Memory (TCM) Up to 64KB
Interrupt Subsystem
IPIC Up to 16 interrupt lines
Debug Subsystem
Interface JTAG/cJTAG-compliant interface
Breakpoints Up to 2 hardware breakpoints, unlimited software breakpoints support
AXI Master AXI4 AMBA standard interface
AHB Master AHB-Lite AMBA standard interface
Timers and Counters
Performance Monitoring 2 performance counters
Embedded 64-bit RTC Timer Machine-mode timer interrupt support

Development Tools

Syntacore Development Toolkit (SCR1 Optimized)

The SC-DT package is a ready-to-use software development kit containing pre-built and pre-configured tools that simplify software development for the SCR1 core. With SC-DT, you can take advantage of the pre-built tools and configurations to reduce the time and effort required to get up and running with SCR1. SC-DT supports Windows and Linux operating systems and includes:

  • Eclipse IDE and Visual Studio Code plugin
  • Compilers (GCC, LLVM) with optimized libraries
  • Debuggers (GDB, OCD)
  • Simulator (QEMU)
  • FreeRTOS
  • BSP and HAL
  • Application examples
  • Benchmarks
  • Documentation

Syntacore also supports and maintains the Zephyr operating system that is not part of the SC-DT package and is downloadable separately.