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AWR1843AOP: Enabling Functional Safety for AWR1843AOP

Part Number: AWR1843AOP
Other Parts Discussed in Thread: AWR1843

Tool/software:

Hi AWR1843AOP Champ !

A customer would like to enable the Functional Safety Features for AWR1843AOP.

They are currently developing a functional safety product targeting SIL-2 (i.e., ASIL-B) using the AWR1843AOP.

Regarding this, the opinion of a functional safety consulting company is that "Based on the content of the AWR1843AOP FMEDA document, all safety mechanisms must be implemented." However, it seems practically challenging to implement all mechanisms ourselves, so we are reaching out for clarification.

Based on our review, we found that in the TI official video "Enabling Functional Safety for mmWave Sensors" (https://www.ti.com/video/6195168655001), at 29 minutes and 21 seconds, it is mentioned that all diagnostic mechanisms can be performed using SDL.

However, it is difficult to determine which safety mechanisms (SM_IDs) are covered by the SDL, and it is unclear whether we need to implement the mechanisms that are not covered.

Thus, the main points of inquiry in this email are as follows:

  1. Do we need to implement all the safety (diagnostic) mechanisms of the AWR1843AOP IC to meet ASIL-B requirements?
  2. If implementing all mechanisms ourselves seems impossible, does TI provide any APIs for implementing these mechanisms?

In addition, there're more inqueries about functional safety from customer side.

Functional Safety

  1. In order to satisfy more than 90% Diagnostic Coverage (DC), do we need to implement all the Diagnostic Mechanism IDs listed in 'Table 17: Diagnostics Mechanisms Summary' of the document 'xWR_Single_Chip_Sensor_Safety_Manual_1.99.pdf'?

  2. If so, the 'Diagnostic Coverage' tab in the 'AWR1843_AOP_FMEDA.xlsm' document, in column C, contains many IDs that are not listed in 'Table 17: Diagnostics Mechanisms Summary'. Which document should we refer to for these IDs?

  3. Additionally, in the AWR1843AOP datasheet (awr1843aop.pdf), 'Table 8-1 Monitoring and Diagnostics' shows diagnostic and monitoring functions that can be enabled via API. If we enable all of these functions, can we satisfy the entire Diagnostic Coverage listed in the 'AWR1843_AOP_FMEDA.xlsm' document, or how will the DC value be affected?

We would appreciate it if you could focus on these points when responding.

Thanks.

Best Regards, Jack

  • Hi Jack,

    Please find my comments below. 

    Do we need to implement all the safety (diagnostic) mechanisms of the AWR1843AOP IC to meet ASIL-B requirements?

    Short answer is no. ASIL-B requirement for the FIT rate is < 100. The device is less than that when SM IDs are implemented. Please check the FMEDA sheet for the exact value. So, as you start eliminating Safety mechanisms that FIT rate will increase. So, it is a tradeoff.  But do not that with the radar a system is designed which will have an external MCU some other peripherals or some other sensors as well. For the system integrator if he wants to claim the entire system design for ASIL- B, then the FIT rate of the entire system should be less than 100. Hence it is not that continent as well to just eliminate mechanisms and increasing the FIT rate of individual elements.

    If implementing all mechanisms ourselves seems impossible, does TI provide any APIs for implementing these mechanisms?

    TI provides an SDL package for this purpose. Users with NDA can ask for this package. TI resource explorer also has a safety demo which shows an example implementation as a reference.   

    In order to satisfy more than 90% Diagnostic Coverage (DC), do we need to implement all the Diagnostic Mechanism IDs listed in 'Table 17: Diagnostics Mechanisms Summary' of the document 'xWR_Single_Chip_Sensor_Safety_Manual_1.99.pdf'?

    Answered above. 

    If so, the 'Diagnostic Coverage' tab in the 'AWR1843_AOP_FMEDA.xlsm' document, in column C, contains many IDs that are not listed in 'Table 17: Diagnostics Mechanisms Summary'. Which document should we refer to for these IDs?

    Can you point them out. 

    Additionally, in the AWR1843AOP datasheet (awr1843aop.pdf), 'Table 8-1 Monitoring and Diagnostics' shows diagnostic and monitoring functions that can be enabled via API. If we enable all of these functions, can we satisfy the entire Diagnostic Coverage listed in the 'AWR1843_AOP_FMEDA.xlsm' document, or how will the DC value be affected?

    No, they are only a part of the Safety diagnostics.

    Thanks,

    Pradipta.