Hydrogen

Hydrogen is our microcontroller platform designed for real-time applications. It features a clean, streamlined architecture that lets you freely combine the inputs and outputs you need. To ensure predictable performance, Hydrogen is built without caches – delivering true real-time responsiveness.

Architecture

The platform is built as a synchronous design with a single clock domain. The CPU connects to the on-chip memory and the peripheral bus via a BMB interconnect with Wishbone interface. By default, a timer and the Platform-Level Interrupt Controller (PLIC) are always connected to this peripheral bus, and additional peripherals can be added as needed.

This simple bus architecture ensures predictable memory access, making it ideal for real-time applications.

Hydrogen includes an SPI XIP (eXecute In Place) interface, allowing code to be loaded and executed directly from external SPI Flash. This enables larger applications without requiring more on-chip memory.

Features

Real-Time Performance

Cache-free architecture ensures predictable, deterministic execution timing. Every memory access has a known, fixed latency, making Hydrogen ideal for hard real-time systems where timing guarantees are critical.

Configurable IOs

Flexible I/O configuration allows you to customize the platform to your exact requirements. Add the peripherals you need without carrying unused hardware, optimizing both resource utilization and power consumption.

External Memory Support

Nitrogen features dedicated interfaces for external memory expansion:

  • SPI XIP Interface: Execute code directly from external SPI Flash without copying to RAM, enabling much larger applications

Zephyr RTOS Ready

Full support for the Zephyr Real-Time Operating System provides access to a mature, well-tested software ecosystem. Leverage thousands of device drivers, networking stacks, and application frameworks to accelerate development.

CPU Core

32-bit RISC-V CPU with a 5-stage pipeline

  • Architecture: RV32IMC (Integer + Multiply/Divide + Compressed)
  • Pipeline: 5-stage in-order execution
  • Integer Operations: Full I extension support
  • M Extension: Hardware multiply and divide
  • C Extension: Compressed instructions for improved code density
  • Shift Operations: Single-cycle barrel shifter
  • Debug Interface: JTAG for development and testing

The RV32IM core provides efficient integer computation with hardware-accelerated multiplication and division, making it suitable for control applications, signal processing, and embedded systems that require deterministic performance.

Technical Specifications

Component Specification
CPU Core 32-bit RISC-V RV32IMC, 5-stage pipeline
Internal Memory Configurable on-chip SRAM
External Memory SPI XIP (SPI Flash)
Bus Architecture BMB interconnect with Wishbone peripheral bus
Clock Frequency 25 MHz (IHP 130nm PDK)
Interrupt Controller PLIC (Platform-Level Interrupt Controller)
Peripherals UART, SPI, I2C, GPIO, Timer (configurable)
Debug JTAG interface
Power Domains Single voltage domain for simplicity
Operating System Zephyr RTOS support included
License Open source, no license fees