SLLA475 December   2020 TCAN1144-Q1 , TCAN1146-Q1

 

  1. 1TCAN1144-Q1 and TCAN1146-Q1 Functional Safety Manual
  2. 2Trademarks
  3. 3Introduction
  4. 4TCAN114x-Q1 Hardware Component Functional Safety Capability
  5. 5Development Process for Management of Systematic Faults
    1. 5.1 TI New-Product Development Process
  6. 6TCAN1144-Q1 and TCAN1146-Q1 Component Overview
    1. 6.1 Targeted Applications
    2. 6.2 Hardware Component Functional Safety Concept
    3. 6.3 Functional Safety Constraints and Assumptions
  7. 7Description of Hardware Component Parts
    1. 7.1 CAN Transceiver
    2. 7.2 Digital Core
    3. 7.3 EEPROM
    4. 7.4 Power Control IP
      1. 7.4.1 Voltage Monitors
    5. 7.5 Thermal Shut Down
    6. 7.6 Digital Input/Outputs
  8. 8TCAN1144-Q1 and TCAN1146-Q1 Management of Random Faults
    1. 8.1 Fault Reporting
    2. 8.2 Functional Safety Mechanism Categories
    3. 8.3 Description of Functional Safety Mechanisms
      1. 8.3.1 CAN Communication
        1. 8.3.1.1 SM-1: CAN bus fault diagnostic
        2. 8.3.1.2 SM-2: Thermal shutdown; TSD
        3. 8.3.1.3 SM-3: CAN bus short circuit limiter, IOS
        4. 8.3.1.4 SM-4: CAN TXD pin dominant state timeout; tTXD_DTO
        5. 8.3.1.5 SM-17: CAN protocol
      2. 8.3.2 Supply Voltage Rail Monitoring
        1. 8.3.2.1 SM-5: VCC undervoltage; UVCC
        2. 8.3.2.2 SM-6: VSUP supply undervoltage; UVSUP
        3. 8.3.2.3 SM-7: VIO supply undervoltage; UVIO
      3. 8.3.3 SPI/Processor Communication
        1. 8.3.3.1 SM-8: Timout, Window or Q&A watchdog error - Normal mode
        2. 8.3.3.2 SM-9: SPI communication error; SPIERR
        3. 8.3.3.3 SM-10: Scratchpad write/read
        4. 8.3.3.4 SM-11: Sleep Wake Error Timer; tINACTIVE
      4. 8.3.4 Device Internal EEPROM
        1. 8.3.4.1 SM-12: Internal memory CRC; CRC_EEPROM
      5. 8.3.5 Floating Pins
        1. 8.3.5.1 SM-13: SCLK internal pull-up to VIO
        2. 8.3.5.2 SM-14: SDI internal pull-up to VIO
        3. 8.3.5.3 SM-15: nCS internal pull-up to VIO
        4. 8.3.5.4 SM-16: TXD internal pull-up to VIO
          1.        B Revision History

6.1 Targeted Applications

The TCAN1144-Q1 and TCAN1146-Q1 components are targeted at general-purpose automotive applications that can support system level functional safety based upon quality managed criteria. This is called Safety Element out of Context (SEooC) development according to ISO 26262-10. In this case, the development is done based on assumptions on the conditions of the semiconductor component usage, and then the assumptions are verified at the system level. This method is also used to meet the related requirements of IEC 61508 at the semiconductor level. This section describes some of the target applications for this component, the component safety concept, and then describes the assumptions about the systems (also know as Assumptions of Use or AoU) that were made in performing the safety analysis.

Example target applications include, but are not limited to, the following:

  • General purpose applications containing a processor and external power.

Figure 6-3 shows a generic block diagram for a general purpose system. This diagram is only an example and may not represent a complete system. Figure 6-4 provides potential failure points that have diagnostic or test ability mechanisms.

GUID-E7B54D31-6EE1-4D1C-8ACB-31AAC54E3A9F-low.gifFigure 6-3 TCAN1144-Q1 and TCAN1146-Q1 General Purpose Application
GUID-20201028-CA0I-HPV1-CVNH-LPHXZPRZV5GN-low.gifFigure 6-4 TCAN1144-Q1 and TCAN1146-Q1 Potential Failure Points
Potential Failure Point from Figure 6-4Potential Failure Point DescriptionSection
1CAN communicationSee Section 8.3.1.1, Section 8.3.1.2, Section 8.3.1.3, Section 8.3.1.4 and Section 8.3.1.5
2Supply voltage rail monitoringSee Section 8.3.2.1, Section 8.3.2.2 and Section 8.3.2.3
3SPI/Processor communicationSee Section 8.3.3.1, Section 8.3.3.2, Section 8.3.3.3 and Section 8.3.3.4
4Device internal EEPROMSee Section 8.3.4.1
5Floating pinsSee Section 8.3.5.1, Section 8.3.5.2, Section 8.3.5.3 and Section 8.3.5.4
Figure 6-5 Potential Failure Points and Safety Mechanism