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.