0.20.0

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

What's Changed

• remove dcd_esp32sx which is replaced by dwc2 by @hathach in #3282
• Fix HID stylus descriptor and hid_composite example by @HiFiPhile in #3280
• fix typo by @hathach in #3283
• fix incorrect MTP xact_len calculation by @RigoLigoRLC in #3284
• stm32h7rs: fix typo in makefile by @HiFiPhile in #3288
• added AGENTS.md by @hathach in #3289
• docs: fix .rst links to use Sphinx :doc: role for proper HTML generation by @Copilot in #3290
• dcd/dwc2: fix enumeration when EP0 size=8 by @HiFiPhile in #3279
• at32_fsdev: Fix dcd_int_enable when remapping the USB interrupt by @tangpipi in #3292
• increase timeout for mtp hil test by @hathach in #3297
• ESP32-S3 bulk transfer issues #3154 by @poornadharshan13-rgb in #3293
• Added stm32l496nucleo board support by @adam-embedded in #3220
• Add qodana CI checks by @qodana-cloud[bot] in #3300
• Revert "Add qodana CI checks" by @hathach in #3302
• add tools that provided freely to develop project by @hathach in #3304
• Initial nrf54h20 support by @hathach in #3299
• Refactor buildsystem and bsp by @hathach in #3306
• More cmake refactor by @hathach in #3316
• Static analysis by @hathach in #3318
• dcd/dwc2: fix suspend interrupt indefinitely disabled on AT32F405 by @peppapighs in #3319
• fix warnings by @hathach in #3320
• examples/device/*_freertos: expand stack size when needed by @karlp in #3271
• try to enable ohci for lpc55 but not working, probably clock issue by @hathach in #3294
• audio: Add UAC1.0 support by @HiFiPhile in #3270
• ohci: Implement support for d-cache operations by @ArcaneNibble in #3248
• Fix code alerts by @hathach in #3326
• fix compile issue with enabled both device and host stack for dwc2 by @hathach in #3333
• Add STM32U3 Device by @tswan22 in #3325
• audio: Implement support for variable EP in flow control fifo level by @gabChouin in #3321
• Fix more code alerts by @hathach in #3334
• Documentation improvements by @c1570 in #3278
• migrate midi_device to use edpt stream API by @hathach in #3337
• migrate cdc device to edpt stream API by @hathach in #3339
• Prevent tu_edpt_number() from returning an invalid endpoint number by @ldube in #3335
• Bufferless (on the fly) video data generation for the video device class by @embedded-ideas in #3322
• make dcd_edpt_iso_alloc/activate as default API for ISO endpoint by @hathach in #3345
• Fix link to Getting Started documentation by @ToonVanEyck in #3347
• dcd/dwc2: fix EP0 multi-packet transfer logic by @HiFiPhile in #3295
• dcd/dwc2: support ISO IN transfer when bInterval > 1 by @HiFiPhile in #3275
• osal/none: add nested count to spin lock by @HiFiPhile in #3151
• host/dwc2: cleanup transfer on device close by @HiFiPhile in #3076
• fix more alerts by @hathach in #3348
• release 0.20.0 by @hathach in #3349
• update changelog.rst by @hathach in #3350

New Contributors

• @RigoLigoRLC made their first contribution in #3284
• @tangpipi made their first contribution in #3292
• @poornadharshan13-rgb made their first contribution in #3293
• @adam-embedded made their first contribution in #3220
• @qodana-cloud[bot] made their first contribution in #3300
• @ArcaneNibble made their first contribution in #3248
• @tswan22 made their first contribution in #3325
• @c1570 made their first contribution in #3278
• @ldube made their first contribution in #3335
• @embedded-ideas made their first contribution in #3322
• @ToonVanEyck made their first contribution in #3347

Full Changelog: 0.19.0...0.20.0