Certification Markets

Reliability for Safety-Critical Markets

Software certification is vital in order to demonstrate the reliability and safety of software systems. Certification requires that products be checked by an independent authority. We serve this market with Cesium RTOS Cs/OS2 and Cs/OS3 real-time kernels that meet the following certification requirements:

 

Market

Certification Standard

Avionics

DO-178B Level E up to Level A

Industrial Controls

IEC 61508 Safety Integrity Level 1 up to Level 3

Medical

IEC 62304 Class A up to Class C [FDA 510(k)]

Automotive

ISO 26262 ASIL D

 

How to Certify

Certification Path

When it comes to certifying your RTOS-based safety-critical application, we provide you with two options:

 

Cesium RTOS

If you are doing the certification work yourself as part of your product development, selecting Cesium RTOS is a sound choice given the code's long history of use in countless functional safety projects.

Flexible Safety RTOS

If you prefer a pre-certified kernel solution, choosing Flexible Safety RTOS for your specified MCU and compiler will reduce time and simplify the development of your safety-critical application.

 

Cesium RTOS Advantages for Certification

 Building your product with our certifiable software components can reduce your certification time and cost. Countless products that rely on our codebase have been already certified in the fields of medical devices, avionics, and industrial controls.

 

Certification requires proof of your source code's origin.

The Cesium RTOS codebase is strictly managed and controlled by Weston Embedded Solutions

Open-source contributions are not allowed

 Ensured codebase integrity

 Simpler documentation trail

 

Our coding rules and naming conventions make the production of documentation for a specific certification much easier.

 Consistent coding rules

 Robust coding standards

 

Long History of Certification

Certification History

The Cesium RTOS is derived from Micrium's µC/OS family of products

 Carefully maintained by the same product experts that brought Micrium's µC/OS to market

 Functional safety characteristics as the original µC/OS are retained in the Cesium RTOS codebase

 

The stability and history of the codebase are of paramount importance in achieving and renewing safety-critical certifications.

 Micrium's µC/OS kernel's first released in 1992

 First safety-critical certification obtained for µC/OS-II in 2000

 

Robustness is Key to Certification

Safety-certified products rely on a stable and bug-free codebase. Thanks to its clean and well-structured design, the Cesium RTOS codebase has a proven track record of reliable operation in even the most demanding real-time applications. The low history of bugs encountered over time reflects the benefits of a mature, well-maintained embedded software product.

 

uCOS2 number of bugs

 

Thousands of products use µC/OS-II in avionics, medical devices, and industrial controls.

 

Comprehensive Coding Standards

We maintain very strict coding rules and styles to which all software that we develop must comply. As a result of meticulous attention to detail, our comprehensive coding standards span over 200 pages. This yields consistent, easily readable, and well-commented code that does not vary from engineer to engineer.

 

Noticeable Standards

 Standard directory structure for files and projects

 Recommended coding style to use (C and Assembly)

 Naming conventions for functions, variables, constants, #defines, macros, etc.

 Acronyms, abbreviations, mnemonics

 Best coding practices

 Mandatory for all employees and contractors

 

Module Prefix and Hierarchy

Every Cesium RTOS software module adheres to a standardized naming system for related functions, #define, constants, variables, and so on. Each is prefixed with the module’s name:

 

Module

Starts with...

Kernel

OS

TCP/IP

Net

USB-Device

USBD

USB-Host

USBH

File System

FS

Modbus Slave

MBS

Modbus Master

MBM

 

This method makes it easier to know which module defines what functionality.

Avoids name clashes

Presents a clear hierarchy

 

Function calls, variables, and constants use a Module-Object-Action naming convention.

OSSemCreate()

OSSemPend()

OSSemPost()

OSIntNestingCtr

OS_CFG_ARG_CHK_EN

 

Comment Headers

 Every function has a comprehensive comment block that documents the function, as shown below. Some comment blocks are highly comprehensive and even contain illustrations. RFCs are referenced in Cs/NET as needed.

Prevent Scheduling

 

Separating Code and Comments

 

Our Code Commenting Standards

Code on the left

Makes it easier to differentiate from comments

Comments on the right

We don't 'pollute' code with comments

Code lined up when appropriate

Function call arguments are lined up one per line

Comments and equal signs are lined up

Numeric values (when appropriate) are lined up by their 'weight'

  

OSTaskStkInit Listing

 

 

Optional Run-Time Argument Checking

 

Run-time argument checking protects code from user errors.

Provides a boundary check on arguments

Return comprehensive error values

 

We do not use obscure constructs or magic numbers.

Validate Arguments

 

 

Designed for Embedded Systems

 

The Cesium RTOS source code

 Is written with resource-limited MCUs in mind

 Always considers code size and RAM usage

 Runs faster by optimizing code size

 Allows disabling argument checking at compile-time in order to streamline the code

 

Run-Time Statistics

 Interrupt disable time

 Scheduler lock time

 Per-task CPU usage

 Can be disabled at compile-time to reduce code and data sizes

Reliable

Cesium software includes comprehensive documentation, full source code, powerful debugging features, and support for a huge range of CPU architectures.

Efficient

Cesium software offers unprecedented ease-of-use, a small memory footprint, remarkable energy efficiency, and all with a full suite of protocol stacks.

Trusted

Engineers across the world building industrial controls, medical devices, and aerospace systems know they can rely on Cesium software for the foundation of exceptional products.