Lightweight USB Device Stack

• Lightweight and fast
• Event-driven process workflow
• Completely separated USB hardware driver and usb core
• Easy to use.

Requirements

• CMSIS V4 or CMSIS V5.
• Device peripheral access layer header files for STM32. See Vendor Template for details.
• stm32.h STM32 universal header

Supported hardware

HW driver	Written on	Endpoints	Features	MCU series
usb_stmv0	GCC C	8	Internal S/N, Doublebuffered, BC1.2	STM32L0x2 STM32L0x3 STM32L4x2 STM32L4x3 STM32F0x2 STM32F0x8
usb_stmv0a	GCC ASM	8	Internal S/N, Doublebuffered, BC1.2	STM32L0x2 STM32L0x3 STM32L4x2 STM32L4x3 STM32F0x2 STM32F0x8
usb_stmv1	GCC C	8	Internal S/N, Doublebuffered	STM32L1xx
usb_stmv1a	GCC ASM	8	Internal S/N, Doublebuffered	STM32L1xx
usb_stmv2	GCC C	6	Internal S/N, Doublebuffered, BC1.2	STM32L4x5 STM32L4x6 (OTG FS Device mode)
usb_stmv3	GCC C	8	Internal S/N, Doublebuffered, optional DP control	STM32F102 STM32F103 STM32F3xx
usb_stmv3a	GCC ASM	8	Internal S/N, Doublebuffered, optional DP control	STM32F102 STM32F103 STM32F3xx

1. Single physical endpoint can be used to implement

• one bi-directional/single-buffer logical endpoint (CONTROL)
• one mono-directional/double-buffer logical endpoint (BULK OR ISOCHRONOUS)
• two mono-directional/single-buffer logical endpoints (BULK OR INTERRUPT)

2. At this moment BULK IN endpoint can use both buffers, but it is not real doublebuffered.

3. Tested with STM32L052, STM31L100, STM32L476RG, STM32F103CB, STM32F303CC, STM32F303RE

Implemented definitions for classes

1. USB HID based on Device Class Definition for Human Interface Devices (HID) Version 1.11
2. USB DFU based on USB Device Firmware Upgrade Specification, Revision 1.1
3. USB CDC based on Class definitions for Communication Devices 1.2

Using makefile

• to build library module

make module MODULE=path/module.a DEFINES="mcu spcified defines" CFLAGS="cpu cpecified compiler flags"

• to build demo

make bluepill program
make stm32l052x8

• to get a help

make help

Default values:

Variable	Default Value	Means
CMSIS	../../CMSIS	path to CMSIS root folder
CMSISDEV	$(CMSIS)/Device	path to CMSIS device folder
CMSISCORE	$(CMSIS)/CMSIS/Include $(CMSIS)/CMSIS/Core/Include	path to CMSIS core headers
MCU	stm32l100xc	MCU selection for demo project
CFLAGS	-mcpu=cortex-m3 -mfloat-abi=soft	MCU specified compiler flags
DEFINES	STM32L1 STM32L100xC	MCU specified defines

Useful Resources

1. USB Implementers Forum official site
2. USB Made Simple
3. LUFA - the Lightweight USB Framework for AVRs.
4. Open Source ARM cortex m microcontroller library