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

8.3.3.1 SM-8: Timout, Window or Q&A watchdog error - Normal mode

The TCAN1144-Q1 and TCAN1146-Q1 support an integrated watchdog function. The devices provide a default window-based watchdog as well as a selectable time-out and question and answer (Q&A) watchdog using the SPI programming. The watchdog timer does not start until the first input trigger event when in normal and standby (when enabled) operational modes. The watchdog timer is off in sleep mode. The INH pin can be programmed as a LIMP function which provides a limp home capability when connected to external circuitry. Otherwise the nINT will reflect a watchdog failure. When in sleep mode, the limp function is off. When the error counter reaches the watchdog trigger event level, the limp pin turns on connecting VSUP to the pin as described in the INH/LIMP pin section. See the data sheet for detailed description on watchdog capability.