0.20.0

November 19, 2025

General

New MCUs and Boards

  • Add STM32U3 device support (adjusted from STM32U0)
  • Add nRF54H20 support with initial board configuration
  • Rename board names: pca10056→nrf52840dk, pca10059→nrf52840dongle, pca10095→nrf5340dk
  • Improve CMake: Move startup and linker files from board target to executable. Enhance target warning flags and fix various build warnings

Code Quality and Static Analysis

  • Add PVS-Studio static analysis to CI
  • Add SonarQube scan support
  • Add IAR C-Stat analysis capability
  • Add .clang-format for consistent code formatting
  • Fix numerous alerts and warnings found by static analysis tools

Documentation

  • Improve Getting Started documentation structure and flow
  • Add naming conventions and buffer handling documentation

Controller Driver (DCD & HCD)

DWC2

  • Fix incorrect handling of Zero-Length Packets (ZLP) in the DWC2 driver when receiving data (OUT transfers)
  • Improve EP0 multi-packet logic
  • Support EP0 with max packet size = 8
  • For IN endpoint, write initial packet directly to FIFO and only use TXFE interrupt for subsequent packets
  • Fix ISO with bInterval > 2 using incomplete IN interrupt handling.
  • Fix compile issues when enabling both host and device
  • Clear pending suspend interrupt after USB reset (enum end)
  • Improve host closing endpoint and channel handling when device is unplugged

FSDEV (STM32)

  • Fix AT32 USB interrupt remapping in dcd_int_enable()

OHCI

  • Add initial LPC55 OHCI support
  • Improve data cache support

Device Stack

USBD Core

  • Support configurable EP0 buffer size CFG_TUD_ENDPOINT0_BUFSIZE
  • Make dcd_edpt_iso_alloc/activate as default API for ISO endpoint

Audio

  • Add UAC1 support
  • Implement RX FIFO threshold adjustment with tud_audio_get/set_ep_in_fifo_threshold()

CDC

  • Migrate to endpoint stream API

HID

  • Fix HID stylus descriptor

MIDI

  • Migrate to endpoint stream API
  • Add tud_midi_n_packet_write_n() and tud_midi_n_packet_read_n()

MTP

  • Fix incorrect MTP xact_len calculation

Video

  • Add bufferless operation callback for dynamic frame generation with tud_video_prepare_payload_cb()

Host Stack

No changes

Contributors

Thanks to everyone who contributed to this release: @adam-embedded, @ArcaneNibble, @c1570, @embedded-ideas, @gabChouin, @hathach, @HiFiPhile, @karlp, @ldube, @peppapighs, @poornadharshan13-rgb, @RigoLigoRLC, @tangpipi, @ToonVanEyck, @tswan22.