Caravel Board

This repo provides firmware examples, flash programming and diagnostic tools for testing Open MPW and chipIgnite projects using Caravel. It also provides schematics, layout and gerber files for PCB evaluation and breakout boards.

MPW-2 & MPW-3 Project Owners

See the README for the the Nucleo automated test setup here

chipIgnite Projects (including Stanford)

See the README for testing projects here -- https://github.com/efabless/caravel_board/tree/main/firmware/chipignite#readme

Firmware

You will need python 3.6 or later.

To program Caravel, connect the evaluation board using a USB micro B connector.

pip3 install pyftdi

cd firmware/blink

make clean flash

Install Toolchain for Compiling Code

For Mac

https://github.com/riscv/homebrew-riscv

For Linux

https://github.com/riscv/riscv-gnu-toolchain

Diagnostics

Makefiles in the firmware project directories use

firmware/chipignite/util/caravel_hkflash.py

to program the flash on the board through Caravel's housekeeping SPI interface.

firmware/chipignite/util/caravel_hkdebug.py

provides menu-driven debug through the housekeeping SPI interface for Caravel.

Hardware

The current evaluation board for Caravel can be found here

• The clock is driven by X1 with a frequency of 10MHz. To drive the clock with custom frequency, disable X1 through J6 and use the external pin for xclk
• The voltage regulator U5 and U6 supply 1.8V and 3.3V through J8 and J9. The traces have to be cut if they are supplied externally.
• vccd1 is connected to 1.8V through J3. The trace has to be cut if it is supplied externally
• vddio is connected to 3.3V through J5. The trace has to be cut if it is supplied externally

The most updated breakout board for Caravel can be found here