a0c53896e0
LXT/HXT are external crystl oscillator and can be absent on custom board.
This enables configuring LXT/HXT presence:
1. By default, LXT/HXT are configured to be present, except M252 which has no HXT.
2. When LXT is configured to not present, lp_ticker/watchdog will clock by LIRC instead.
3. Limitations:
(1) On all targets, LIRC-clocked lp_ticker gets inaccurate and fails to pass tests.
(2) On NUC472/M453, HIRC-clocked PLL doesn't output 1MHz-aligned frequency. us_ticker gets slight inaccurate.
(3) On all targets, LIRC-clocked RTC is not supported due to no H/W path/RTC clock source reset to LXT on reset/RTC not trimmed for other clock rates.
4. On M263, TRNG's clock source defaults to LXT and needs special handling without LXT.
5. On M252, replace target.hxt-enable with target.hxt-present for consistency.
|
||
|---|---|---|
| .github | ||
| TESTS | ||
| TEST_APPS | ||
| UNITTESTS | ||
| cmsis | ||
| connectivity | ||
| docs | ||
| drivers | ||
| events | ||
| features | ||
| hal | ||
| platform | ||
| rtos | ||
| storage | ||
| targets | ||
| tools | ||
| .astylerc | ||
| .codecheckignore | ||
| .coveragerc | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .mergify.yml | ||
| .pylintrc | ||
| .travis.yml | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| DOXYGEN_FRONTPAGE.md | ||
| Jenkinsfile | ||
| LICENSE-apache-2.0.txt | ||
| LICENSE.md | ||
| README.md | ||
| doxyfile_options | ||
| doxygen_options.json | ||
| logo.png | ||
| mbed.h | ||
| requirements.txt | ||
README.md
Arm Mbed OS is an open source embedded operating system designed specifically for the "things" in the Internet of Things. It includes all the features you need to develop a connected product based on an Arm Cortex-M microcontroller, including security, connectivity, an RTOS and drivers for sensors and I/O devices.
Mbed OS provides a platform that includes:
- Security foundations.
- Cloud management services.
- Drivers for sensors, I/O devices and connectivity.
Release notes
The release notes detail the current release. You can also find information about previous versions.
License and contributions
The software is provided under the Apache-2.0 license. Contributions to this project are accepted under the same license. Please see contributing.md for more information.
This project contains code from other projects. The original license text is included in those source files. They must comply with our license guide.
Folders containing files under different permissive license than Apache 2.0 are listed in the LICENSE file.
Getting started for developers
We have a developer website for asking questions, engaging with others, finding information on boards and components, using an online IDE and compiler, reading the documentation and learning about what's new and what's coming next in Mbed OS.
Getting started for contributors
We also have a contributing and publishing guide that covers licensing, contributor agreements and style guidelines.
Documentation
For more information about Mbed OS, please see our published documentation. It includes Doxygen for our APIs, step-by-step tutorials, porting information and background reference materials about our architecture and tools.
To contribute to this documentation, please see the mbed-os-5-docs repository.