SFFS889 July   2024 TMS320F2800132 , TMS320F2800133 , TMS320F2800135 , TMS320F2800137

 

  1.   1
  2.   Trademarks
  3. 1Introduction
  4. 2TMS320F280013x Hardware Component Functional Safety Capability
  5. 3TI Development Process for Management of Systematic Faults
    1. 3.1 TI New-Product Development Process
    2. 3.2 TI Functional Safety Development Process
  6. 4Component Overview
    1. 4.1 Targeted Applications
      1. 4.1.1 TMS320F280013x MCU
    2. 4.2 Hardware Component Functional Safety Concept
      1. 4.2.1 TMS320F280013x MCU Safety Features
      2. 4.2.2 Fault Tolerant Time Interval (FTTI)
      3. 4.2.3 TMS320F280013x MCU Safe State
      4. 4.2.4 Operating States
    3. 4.3 Hardware Component Configuration
      1. 4.3.1 Assumptions of Use - F280013x Self-Test Libraries
      2. 4.3.2 Operational Details - SDL
        1. 4.3.2.1 Operational Details – SDL Module Mapping
    4. 4.4 TMS320F280013x MCU Safety Implementation
      1. 4.4.1 Assumptions of Use
      2. 4.4.2 Example Safety Concept Implementation Options on TMS320F280013x MCU
  7. 5Description of Safety Elements
    1. 5.1 TMS320F280013x MCU Infrastructure Components
      1. 5.1.1 Power Supply
      2. 5.1.2 Clock
      3. 5.1.3 APLL
      4. 5.1.4 Reset
      5. 5.1.5 System Control Module and Configuration Registers
      6. 5.1.6 JTAG Debug, Trace, Calibration, and Test Access
    2. 5.2 Processing Elements
      1. 5.2.1 C28x Central Processing Unit (CPU)
    3. 5.3 Memory (Flash, SRAM and ROM)
      1. 5.3.1 Embedded Flash Memory
      2. 5.3.2 Embedded SRAM
      3. 5.3.3 Embedded ROM
    4. 5.4 On-Chip Communication Including Bus Arbitration
      1. 5.4.1 Device Interconnect
      2. 5.4.2 Enhanced Peripheral Interrupt Expander (ePIE) Module
      3. 5.4.3 Dual Zone Code Security Module (DCSM)
      4. 5.4.4 Crossbar (X-BAR)
      5. 5.4.5 Timer
    5. 5.5 Digital I/O
      1. 5.5.1 General-Purpose Input/Output (GPIO) and Pinmuxing
      2. 5.5.2 Enhanced Pulse Width Modulators (ePWM)
      3. 5.5.3 High Resolution PWM (HRPWM)
      4. 5.5.4 Enhanced Capture (eCAP)
      5. 5.5.5 Enhanced Quadrature Encoder Pulse (eQEP)
      6. 5.5.6 External Interrupt (XINT)
    6. 5.6 Analog I/O
      1. 5.6.1 Analog-to-Digital Converter (ADC)
      2. 5.6.2 Comparator Subsystem (CMPSS)
    7. 5.7 Data Transmission
      1. 5.7.1 Controller Area Network (DCAN)
      2. 5.7.2 Serial Peripheral Interface (SPI)
      3. 5.7.3 Serial Communication Interface (SCI)
      4. 5.7.4 Inter-Integrated Circuit (I2C)
  8. 6Management of Random Faults
    1. 6.1 Fault Reporting
      1. 6.1.1 Suggestions for Improving Freedom From Interference
      2. 6.1.2 Suggestions for Addressing Common Cause Failures
    2. 6.2 Functional Safety Mechanism
    3. 6.3 Description of Functional Safety Mechanisms
      1. 6.3.1 TMS320F280013x MCU Infrastructure Components
        1. 6.3.1.1  Clock Integrity Check Using DCC
        2. 6.3.1.2  Clock Integrity Check Using CPU Timer
        3. 6.3.1.3  Clock Integrity Check Using HRPWM
        4. 6.3.1.4  EALLOW Protection for Critical Registers
        5. 6.3.1.5  External Monitoring of Clock via XCLKOUT
        6. 6.3.1.6  External Monitoring of Warm Reset (XRSn)
        7. 6.3.1.7  External Voltage Supervisor
        8. 6.3.1.8  External Watchdog
        9. 6.3.1.9  Glitch Filtering on Reset Pins
        10. 6.3.1.10 Hardware Disable of JTAG Port
        11. 6.3.1.11 Lockout of JTAG Access Using OTP
        12. 6.3.1.12 Internal Watchdog (WD)
        13. 6.3.1.13 Lock Mechanism for Control Registers
        14. 6.3.1.14 Missing Clock Detect (MCD)
        15. 6.3.1.15 NMIWD Reset Functionality
        16. 6.3.1.16 NMIWD Shadow Registers
        17. 6.3.1.17 Multi-Bit Enable Keys for Control Registers
        18. 6.3.1.18 Online Monitoring of Temperature
        19. 6.3.1.19 Periodic Software Read Back of Static Configuration Registers
        20. 6.3.1.20 Peripheral Clock Gating (PCLKCR)
        21. 6.3.1.21 Peripheral Soft Reset (SOFTPRES)
        22. 6.3.1.22 Software Test of Reset - Type 1
        23. 6.3.1.23 PLL Lock Profiling Using On-Chip Timer
        24. 6.3.1.24 Reset Cause Information
        25. 6.3.1.25 Software Read Back of Written Configuration
        26. 6.3.1.26 Software Test of ERRORSTS Functionality
        27. 6.3.1.27 Software Test of Missing Clock Detect Functionality
        28. 6.3.1.28 Software Test of Watchdog (WD) Operation
        29. 6.3.1.29 Dual-Clock Comparator (DCC) - Type 2
        30. 6.3.1.30 PLL Lock Indication
        31. 6.3.1.31 Software Test of DCC Functionality Including Error Tests
        32. 6.3.1.32 Software Test of PLL Functionality Including Error Tests
        33. 6.3.1.33 Interleaving of FSM States
        34. 6.3.1.34 Brownout Reset (BOR)
      2. 6.3.2 Processing Elements
        1. 6.3.2.1 CPU Handling of Illegal Operation, Illegal Results, and Instruction Trapping
        2. 6.3.2.2 Stack Overflow Detection
        3. 6.3.2.3 CRC Check of Static Memory Contents
      3. 6.3.3 Memory (Flash, SRAM and ROM)
        1. 6.3.3.1  Bit Multiplexing in Flash Memory Array
        2. 6.3.3.2  Bit Multiplexing in SRAM Memory Array
        3. 6.3.3.3  Data Scrubbing to Detect/Correct Memory Errors
        4. 6.3.3.4  Flash ECC
        5. 6.3.3.5  Flash Program Verify and Erase Verify Check
        6. 6.3.3.6  Flash Program/Erase Protection
        7. 6.3.3.7  Flash Wrapper Error and Status Reporting
        8. 6.3.3.8  Prevent 0 to 1 Transition Using Program Command
        9. 6.3.3.9  On-Demand Software Program Verify and Blank Check
        10. 6.3.3.10 CMDWEPROT* and Program Command Data Buffer Registers Self-Clear After Command Execution
        11. 6.3.3.11 ECC Generation and Checker Logic is Separate in Hardware
        12. 6.3.3.12 Auto ECC Generation Override
        13. 6.3.3.13 Software Test of ECC Logic
        14. 6.3.3.14 Software Test of Flash Prefetch, Data Cache, and Wait-States
        15. 6.3.3.15 Access Protection Mechanism for Memories
        16. 6.3.3.16 SRAM ECC
        17. 6.3.3.17 SRAM Parity
        18. 6.3.3.18 Software Test of Parity Logic
        19. 6.3.3.19 Software Test of SRAM
        20. 6.3.3.20 Memory Power-On Self-Test (MPOST)
        21. 6.3.3.21 ROM Parity
      4. 6.3.4 On-Chip Communication Including Bus-Arbitration
        1. 6.3.4.1 1oo2 Software Voting Using Secondary Free Running Counter
        2. 6.3.4.2 Maintaining Interrupt Handler for Unused Interrupts
        3. 6.3.4.3 Power-Up Pre-Operational Security Checks
        4. 6.3.4.4 Majority Voting and Error Detection of Link Pointer
        5. 6.3.4.5 Software Check of X-BAR Flag
        6. 6.3.4.6 Software Test of ePIE Operation Including Error Tests
      5. 6.3.5 Digital I/O
        1. 6.3.5.1  eCAP Application Level Safety Mechanism
        2. 6.3.5.2  ePWM Application Level Safety Mechanism
        3. 6.3.5.3  ePWM Fault Detection Using X-BAR
        4. 6.3.5.4  ePWM Synchronization Check
        5. 6.3.5.5  eQEP Application Level Safety Mechanism
        6. 6.3.5.6  eQEP Quadrature Watchdog
        7. 6.3.5.7  eQEP Software Test of Quadrature Watchdog Functionality
        8. 6.3.5.8  Hardware Redundancy
        9. 6.3.5.9  HRPWM Built-In Self-Check and Diagnostic Capabilities
        10. 6.3.5.10 Information Redundancy Techniques
        11. 6.3.5.11 Monitoring of ePWM by eCAP
        12. 6.3.5.12 Monitoring of ePWM by ADC
        13. 6.3.5.13 Online Monitoring of Periodic Interrupts and Events
        14. 6.3.5.14 Software Test of Function Including Error Tests
        15. 6.3.5.15 QMA Error Detection Logic
      6. 6.3.6 Analog I/O
        1. 6.3.6.1 ADC Information Redundancy Techniques
        2. 6.3.6.2 ADC Input Signal Integrity Check
        3. 6.3.6.3 ADC Signal Quality Check by Varying Acquisition Window
        4. 6.3.6.4 CMPSS Ramp Generator Functionality Check
        5. 6.3.6.5 DAC to ADC Loopback Check
        6. 6.3.6.6 Opens/Shorts Detection Circuit for ADC
        7. 6.3.6.7 Disabling Unused Sources of SOC Inputs to ADC
      7. 6.3.7 Data Transmission
        1. 6.3.7.1  Information Redundancy Techniques Including End-to-End Safing
        2. 6.3.7.2  Bit Error Detection
        3. 6.3.7.3  CRC in Message
        4. 6.3.7.4  DCAN Acknowledge Error Detection
        5. 6.3.7.5  DCAN Form Error Detection
        6. 6.3.7.6  DCAN Stuff Error Detection
        7. 6.3.7.7  Software Test of Function Including Error Tests Using EPG
        8. 6.3.7.8  I2C Access Latency Profiling Using On-Chip Timer
        9. 6.3.7.9  I2C Data Acknowledge Check
        10. 6.3.7.10 Parity in Message
        11. 6.3.7.11 SCI Break Error Detection
        12. 6.3.7.12 Frame Error Detection
        13. 6.3.7.13 Overrun Error Detection
        14. 6.3.7.14 Software Test of Function Using I/O Loopback
        15. 6.3.7.15 SPI Data Overrun Detection
        16. 6.3.7.16 Transmission Redundancy
  9.   A Summary of Safety Features and Diagnostics
  10.   B References

6.3.5.14 Software Test of Function Including Error Tests

A software test can be utilized to test the basic functionality of the module and to inject diagnostic errors and check for a proper error response. Such tests can be executed at boot or periodically. Necessary software requirements are defined by the software implemented by the system integrator.

Ideas for creating some module-specific functionality and error tests are given below:

  • Software tests of the input and output X-BAR module can be performed by having a loop created (output X-BAR can be used as stimulus to input X-BAR) using the input and output X-BAR, sending a known test sequence at the input and observing the final output. Integrity of ePWM X-BAR can be checked by sending the test stimulus and observing the response using ePWM trip or sync functionality.
  • Software test of XINT functionality can be checked by configuring the input X-BAR and forcing the corresponding GPIO register to generate an interrupt. The diagnostic coverage can be enhanced by performing checks for the polarity (XINTxCR.POLARITY) and the enable (XINTxCR.ENABLE) functionalities as well.
  • eCAP and eQEP functionality can be checked by looping back the PWM, HRPWM, or GPIO outputs to the respective module inputs, providing a known-good sequence, as required by the module, and observing the module output. In the case of eCAP, the test can be done internally with the help of input X-BAR.
  • ROM prefetch functionality can be checked using similar techniques as given in Section 6.3.3.14.
  • The ePWM module consists of time-base (TB), counter compare (CC), action qualifier (AQ), dead-band generator (DB), PWM chopper (PC), trip zone (TZ), event trigger (ET) and digital compare (DC) sub-modules. The individual sub-modules can be tested by providing appropriate stimulus using ePWM and observing the response using one of the capture (time stamping) modules (eCAP, XINT, eQEP, and so forth). TI recommends covering the various register values associated with application configuration while performing the software test. Due to the regular linear nature of the various sub-modules, getting high coverage is possible using a software test.
  • A software test of SRAM wrapper logic must provide diagnostic coverage for arbitration between various controllers having access to the particular SRAM and correct functioning of access protection. This is in addition to the test used to provide coverage of SRAM bit cells (see Section 6.3.3.19).
  • The interconnect (INC) functionality can be tested by writing complimentary data-patterns, such as 0xA5A5, 0x5A5A, or other common test cases, to the processing units in the CPU and reading those patterns back from the registers of the various IPs connected through different interconnect bridges. The read-back data can be compared with expected golden values to verify a fault-free interconnect operation. This exercise can be repeated for different data width types of accesses (16 and 32 bits) and wide address ranges, as applicable. The CPU accesses can be repeated for different instances of peripherals used in application connected to various bridges as shown in Figure 4-1.
  • To test core functionality of the ADC module and post processing block (PPB), a set of predetermined voltage levels can be provided on the ADC input pin by external circuit or internal DAC. The ADC and PPB results obtained can be cross checked against the expected value to verify proper operation. Extreme corner values of the ADC used in an application can be applied and tested to check the successful conversion across the operational range. ADC configuration registers can be checked by writing complementary data-patterns that are read back and compared to expected values.
  • Comparator sub-system (CMPSS) has a set of registers which can be checked by writing complementary data-patterns, like 0xA5A5, 0x5A5A, and so forth, in both 16 and 32 bit access modes. These data-patterns are read back and compared against the expected values. Features of the CMPSS module, such as ramp decrement, can be checked for counting down of RAMPDLYA after RAMPDLYA is loaded from RAMPDLYS by a rising PWMSYNC signal. Always verify that the decrementer reduces to zero and stays there until next reload from RAMPDLYS. Extreme values of RAMPDLYS can be configured before count down. Digital filter CTRIPHFILCTL/CTRIPLFILCTL registers can be checked by configuring the registers to a variety of SAMPWIN (sample window) and THRESH (majority voting threshold) values, and then verifying COMPHSTS/COMPLSTS changes with changes in the filter output. An applicable range of filter-clock, pre-scaler values (CTRIPLFILCLKCTL) can be exercised to verify that the filter samples correctly.
  • The general operation of the CPU timers can be tested through a software test by loading 32-bit counter register TIMH from period register PRDH. The TIMH counter register then starts decrementing on every clock cycle. When the counter reaches zero, a timer-interrupt output generates an interrupt pulse. While testing the timer functionality, vary the timer prescale counter (TPR) value and input clocks by selecting the clock source as SYSCLK, INTOSC1, INTOSC2, or XTAL. Interrupt generation can be tested at the end of each timer period. Check for the time overflow flag and timer reload (TRB) functions in TCR register for correct functioning.
  • A software test function in DCSM can be implemented independently in zone1, zone2, and unsecured zone to check DCSM functionality. Device security configurations are loaded from OTP to DCSM during the device boot phase. The test function can implement access filtering checks (read-write and execute permissions) to RAMs and flash sectors belonging to the same zone and different zone. An additional check for EXEONLY configuration can also be implemented for the RAMs and flash sectors to verify that all access, other than execute access, is blocked.