Aug 06, 2023

OpenHW Group Opens Orders for the Open

The OpenHW Group, an organization set up to promote free and open source silicon efforts, is launching an in-house microcontroller development board designed to get users started with its 32-bit RISC-V RV32E40P processor core: the CORE-V MCU DevKit.

"The CORE-V MCU DevKit is a turnkey, open source development and prototyping platform for the CORE-V MCU System on Chip [SoC]," the OpenHW Group writes in support of the device's launch. "The CORE-V MCU DevKit enables makers of IoT [Internet of Things] and embedded systems to evaluate the performance of the CORE-V MCU, to interconnect with Wi-Fi and the IoT cloud, and to develop and test software using the CORE-V SDK [Software Development Kit]."

The heart of the board is the CV32E40Pv1 processor core, a four-stage in-order 32-bit RISC-V implementation released by the group under the permissive Solderpad 2.1 license. Fully open, the core includes the basic 32-bit RISC-V integer instructions plus extensions for multiplication and division, performance counters, control and status registers, instruction-fetch fencing, and compressed instructions.

This core in turn lives within the CORE-V MCU, a microcontroller built using GlobalFoundries' 22FDX process and combining the C32E40P with peripherals, memory, and an ArcticPro 2 embedded FPGA (eFPGA) from Quicklogic — with everything bar the eFPGA also made available under the Solderpad 2.1 license. The chip includes 512kB of static RAM, two UART, QSPI, I2C, and one SDIO buses, a camera interface, a separate I2C client interface, a pulse-width modulation (PWM) timer with four channels, JTAG debugging support, and 32 general-purpose input/output (GPIO) pins.

Elsewhere on the board is an AWS IoT ExpressLink module with Wi-Fi connectivity to the AWS IoT ExpressLink cloud platform, a mikroBUS header, an on-board I2C temperature sensor, user-addressable LEDs, a single user- a USB Type-C connector for data, power, and debugging, 4MB of flash memory, and a connector for an optional 5-18V DC power supply. The bundle also includes a Himax low-power CMOS camera sensor, connected via a flexible ribbon cable.

For the software side, the OpenHW Group has provided an open source software development kit (SDK), including an Eclipse-based integrated development environment (IDE), the FreeRTOS real-time operating system, a GNU GCC toolchain, peripheral driver libraries, and example code. This is compatible with Windows 10, Windows 11, and Linux on 64-bit x86 hardware — with neither Arm nor, ironically, RISC-V hosts yet supported.

The not-for-profit is taking orders for the CORE-V MCU DevKit via GroupGets at $199 plus shipping, with hardware expected to begin delivery in November; at the time of writing, it had raised 63 percent of its 180-unit funding goal.