CherryUSB

CherryUSB is a tiny, beautiful and portable USB host and device stack for embedded system with USB ip.

Why choose

Ip-oriented programming, the same usb ip driver does not need to be written repeatedly, only the parts that are not the same need to be implemented
Code tree writing makes it easier for users to understand usb concept, enumeration process, class driver loading
Templating the Class driver makes it easier to use composite device and add custom drivers
Simplifying the complex transfer of usb makes it easier for users to use usb as easily as uart and dma
Fewer directory structures, fewer apis, fewer codesize, extreme usb bandwidth

Directoy Structure

.
├── class
├── common
├── core
├── demo
├── docs
├── osal
├── packet capture
└── port
└── tools

Directory	Description
class	usb class driver
common	usb spec macros and utils
core	usb core implementation
demo	different chips demo
osal	os wrapper
docs	doc for guiding
packet capture	packet capture file
port	usb dcd and hcd porting
tools	tool used url

Device Stack Overview

CherryUSB Device Stack provides a unified framework of functions for standard device requests, CLASS requests, VENDOR requests and custom special requests. The object-oriented and chained approach allows the user to quickly get started with composite devices without having to worry about the underlying logic. At the same time, a standard dcd porting interface has been standardised for adapting different USB IPs to achieve ip-oriented programming.

CherryUSB Device Stack has the following functions：

Support USB2.0 full and high speed
Support endpoint irq callback register by users, let users do whatever they wants in endpoint irq callback.
Support Composite Device
Support Communication Device Class (CDC)
Support Human Interface Device (HID)
Support Custom human Interface Device (HID)
Support Mass Storage Class (MSC)
Support USB VIDEO CLASS (UVC1.0、UVC1.5)
Support USB AUDIO CLASS (UAC1.0、UAC2.0)
Support Device Firmware Upgrade CLASS (DFU)
Support USB MIDI CLASS (MIDI)
Support Test and Measurement CLASS (TMC)
Support Remote NDIS (RNDIS)
Support WINUSB1.0、WINUSB2.0(with BOS)
Support Vendor class

CherryUSB Device Stack resource usage (GCC 10.2 with -O2)：

file	FLASH (Byte)	RAM (Byte)
usbd_core.c	3045	373
usbd_cdc.c	302	20
usbd_msc.c	2452	132
usbd_hid.c	784	201
usbd_audio.c	438	14
usbd_video.c	402	4

Host Stack Overview

The CherryUSB Host Stack has a standard enumeration implementation for devices mounted on roothubs and external hubs, and a standard interface for the different Class to indicate what the Class driver needs to do after enumeration and after disconnection. A standard hcd porting interface has also been standardised for adapting different USB IPs for IP-oriented programming. Finally, the protocol stack is managed using os, and provides osal to make a adaptation to different os.

CherryUSB Host Stack has the following functions：

Automatic loading of supported Class drivers
Support blocking transfers and asynchronous transfers
Support Composite Device
Multi-level HUB support, expandable up to 7 levels
Support Communication Device Class (CDC)
Support Human Interface Device (HID)
Support Mass Storage Class (MSC)
Support Remote NDIS (RNDIS)
Support Vendor class

The CherryUSB Host stack also provides the lsusb function, which allows you to view information about all mounted devices, including those on external hubs, with the help of a shell plugin.

Documentation Tutorial

Quickly start, USB basic concepts, API manual, Class basic concepts and examples, see CherryUSB Documentation Tutorial

Video Tutorial

USB basic concepts and how the CherryUSB Device stack is implemented, see CherryUSB Device Stack Tutorial.

Graphical Config Tool

chryusb_configurator is written in electron + vite2 + ts framework，currently used to automate the generation of descriptor arrays, with additional functionality to be added later.

CherryUSB / cherryusb_mm32