SPRUID8D September 2020 – January 2022 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
This section provides the high level details related to what a system integrator must consider during the process of defining and building their F28004x based safety architecture.
The software support for the various safety mechanisms in the F28004x can be divided into the following three categories:
A safe product built on the F28004x device hierarchically deploys each of the software solutions provided by TI. The first in the hierarchy is the C28x_STL which detect permanent faults inside the CPU by implementing the CPU3 - Software Test of CPU safety mechanism. The second in the hierarchy is the SDL which provides a series of examples of safety mechanisms that are designed to detect permanent faults inside several key elements within the F28004x device. Lastly, the CLA_STL which implements the CLA2 - Software Test of CLA safety mechanism, can be deployed to detect permanent faults inside the CLA.
The CLA_STL makes use of, and depends on both the C28x CPU and the CLA to test the CLA. Therefore it is important to run the C28x_STL first to make sure that the CPU is functioning properly and is capable of performing the required safety operations. The SDL supports safety mechanisms such as: CLK2 - Clock Integrity Check Using CPU Timer, CLK10 - Software Test of Watchdog (WD) Operation, CLK12 - Software Test of Missing Clock Detect Functionality, SRAM14 - Software Test of Parity Logic, SRAM13 - Software Test of ECC Logic, SRAM3 - Software Test of SRAM and several other key processing elements. The system integrator must study all the safety mechanisms supported by the SDL and determine their applicability into the safety system being designed. The safety system must be evaluated with respect to the startup and runtime constraints and whether the software diagnostic tests can be run during POST, PEST or a combination of both.
The successful completion of the software diagnostics, selected by the system integrator, can be used as the qualifier to run the test vectors supported by the CLA_STL.