.. zephyr:board:: elemrv

Overview

ElemRV-N is an end-to-end open-source RISC-V microcontroller designed using SpinalHDL.

Version 0.2 of ElemRV-N was successfully fabricated using IHP's Open PDK, a 130nm open semiconductor process, with support from FMD-QNC.

For more details, refer to the official GitHub Project_.

.. note:: The currently supported silicon version is ElemRV-N 0.2.

Supported Features

.. zephyr:board-supported-hw::

System Clock

The system clock for the RISC-V core is set to 20 MHz. This value is specified in the cpu0 devicetree node using the clock-frequency property.

CPU

ElemRV-N integrates a VexRiscv RISC-V core featuring a 5-stage pipeline and the following ISA extensions:

M (Integer Multiply/Divide)
C (Compressed Instructions)

It also includes the following general-purpose Z extensions:

Zicntr – Base Counter and Timer extensions
Zicsr – Control and Status Register operations
Zifencei – Instruction-fetch fence

The complete ISA string for this CPU is: RV32IMC_Zicntr_Zicsr_Zifencei

Hart-Level Interrupt Controller (HLIC)

Each CPU core is equipped with a Hart-Level Interrupt Controller, configurable through Control and Status Registers (CSRs).

Machine Timer

A RISC-V compliant machine timer is enabled by default.

Serial

The UART (Universal Asynchronous Receiver-Transmitter) interface is a configurable serial communication peripheral used for transmitting and receiving data.

By default, uart0 operates at a baud rate of 115200, which can be adjusted via the elemrv device tree.

To evaluate the UART interface, build and run the following sample:

.. zephyr-app-commands:: :board: elemrv/elemrv_n :zephyr-app: samples/hello_world :goals: build

GPIO

The GPIO (General-Purpose Input/Output) interface with tri-state pins is a digital interface that allows each pin to be configured as either an input or an output, with additional control for setting the direction of data flow.

gpio consists of a total of 12 individual pins.

The Blinky sample provides a simple way to explore how a GPIO can be used to control an external LED.

.. zephyr-app-commands:: :board: elemrv/elemrv_n :zephyr-app: samples/basic/blinky :goals: build

.. _GitHub Project: https://github.com/aesc-silicon/elemrv

.. _IHP's Open PDK: https://github.com/IHP-GmbH/IHP-Open-PDK

.. _FMD-QNC: https://www.elektronikforschung.de/projekte/fmd-qnc