SPRUIT5 April   2021 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2TMS320F28002x Product Safety Capability and Constraints
  4. 3TI Development Process for Management of Systematic Faults
    1. 3.1 TI New-Product Development Process
    2. 3.2 TI Safety Development Process
  5. 4TMS320F28002x Product Overview
    1. 4.1 C2000 Architecture and Product Overview
      1. 4.1.1 TMS320F28002x MCU
    2. 4.2 Functional Safety Concept
      1. 4.2.1 TMS320F28002x MCU Safety Features
      2. 4.2.2 Fault Tolerant Time Interval (FTTI)
      3. 4.2.3 TMS320F28002x MCU Safe State
      4. 4.2.4 Operating States
      5. 4.2.5 Management of Faults
      6. 4.2.6 Suggestions for Improving Freedom From Interference
      7. 4.2.7 Suggestions for Addressing Common Cause Failures
    3. 4.3 C2000 Safety Diagnostics Libraries
    4. 4.4 TMS320F28002x MCU Safety Implementation
      1. 4.4.1 Assumed Safety Requirements
        1. 4.4.1.1 Example Safety Concept Implementation Options on TMS320F28002x MCU
          1. 4.4.1.1.1 Safety Concept Implementation
  6. 5Brief Description of Safety Elements
    1. 5.1 TMS320F28002x MCU Infrastructure Components
      1. 5.1.1 Power Supply
      2. 5.1.2 Clock
      3. 5.1.3 System PLL
      4. 5.1.4 Reset
      5. 5.1.5 System Control Module and Configuration Registers
      6. 5.1.6 Efuse Static Configuration
      7. 5.1.7 JTAG Debug, Trace, Calibration, and Test Access
    2. 5.2 Processing Elements
      1. 5.2.1 C28x Central Processing Unit (CPU)
      2. 5.2.2 Diagnostics for CPU
      3. 5.2.3 Floating Point Unit (FPU)
    3. 5.3 Memory (Flash, SRAM and ROM)
      1. 5.3.1 Embedded Flash Memory
      2. 5.3.2 Diagnostics for Embedded Flash
      3. 5.3.3 Embedded SRAM
      4. 5.3.4 Embedded ROM
    4. 5.4 On-Chip Communication Including Bus-Arbitration
      1. 5.4.1 Device Interconnect
      2. 5.4.2 Direct Memory Access (DMA)
      3. 5.4.3 Enhanced Peripheral Interrupt Expander (ePIE) Module
      4. 5.4.4 Dual Zone Code Security Module (DCSM)
      5. 5.4.5 CrossBar (X-BAR)
      6. 5.4.6 Timer
      7. 5.4.7 Configurable Logic Block
    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 High Resolution Capture (HRCAP)
      6. 5.5.6 Enhanced Quadrature Encoder Pulse (eQEP)
      7. 5.5.7 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)
      5. 5.7.5 Fast Serial Interface (FSI)
      6. 5.7.6 Local Interconnect Network (LIN)
      7. 5.7.7 Power Management Bus Module (PMBus)
      8. 5.7.8 Host Interface Controller (HIC)
  7. 6Brief Description of Diagnostics
    1. 6.1 TMS320F28002x MCU Infrastructure Components
      1. 6.1.1  Clock Integrity Check Using CPU Timer
      2. 6.1.2  Clock Integrity Check Using HRPWM
      3. 6.1.3  Clock Integrity Check Using DCC
      4. 6.1.4  EALLOW Protection for Critical Registers
      5. 6.1.5  Efuse Autoload Self-Test
      6. 6.1.6  Efuse ECC
      7. 6.1.7  Efuse ECC Logic Self-Test
      8. 6.1.8  External Monitoring of Clock via XCLKOUT
      9. 6.1.9  External Monitoring of Warm Reset (XRSn)
      10. 6.1.10 External Voltage Supervisor
      11. 6.1.11 External Watchdog
      12. 6.1.12 Glitch Filtering on Reset Pins
      13. 6.1.13 Hardware Disable of JTAG Port
      14. 6.1.14 Internal Watchdog (WD)
      15. 6.1.15 Lock Mechanism for Control Registers
      16. 6.1.16 Missing Clock Detect (MCD)
      17. 6.1.17 NMIWD Reset Functionality
      18. 6.1.18 NMIWD Shadow Registers
      19. 6.1.19 Multi-Bit Enable Keys for Control Registers
      20. 6.1.20 Online Monitoring of Temperature
      21. 6.1.21 Periodic Software Read Back of Static Configuration Registers
      22. 6.1.22 Peripheral Clock Gating (PCLKCR)
      23. 6.1.23 Peripheral Soft Reset (SOFTPRES)
      24. 6.1.24 PLL Lock Profiling Using On-Chip Timer
      25. 6.1.25 PLL lock indication
      26. 6.1.26 Reset Cause Information
      27. 6.1.27 Software Read Back of Written Configuration
      28. 6.1.28 Software Test of ERRORSTS Functionality
      29. 6.1.29 Software Test of Missing Clock Detect Functionality
      30. 6.1.30 Software test of DCC functionality including error tests
      31. 6.1.31 Interleaving of FSM states
      32. 6.1.32 Software Test of Reset
      33. 6.1.33 Software Test of Watchdog (WD) Operation
      34. 6.1.34 Brownout Reset (BOR)
      35. 6.1.35 Dual clock comparator (DCC) - Type 2
    2. 6.2 Processing Elements
      1. 6.2.1  CPU Hardware Built-In Self-Test (HWBIST)
      2. 6.2.2  CPU Hardware Built-In Self-Test (HWBIST) Auto-Coverage
      3. 6.2.3  CPU Hardware Built-In Self-Test (HWBIST) Timeout Feature
      4. 6.2.4  CPU Hardware Built-In Self-Test (HWBIST) Fault Injection Capability
      5. 6.2.5  CPU Handling of Illegal Operation, Illegal Results and Instruction Trapping
      6. 6.2.6  Stack Overflow Detection
      7. 6.2.7  VCRC Check of Static Memory Contents
      8. 6.2.8  VCRC Auto Coverage
      9. 6.2.9  Embedded Real Time Analysis and Diagnostic (ERAD)
      10. 6.2.10 Inbuilt hardware redundancy in ERAD bus comparator module
    3. 6.3 Memory (Flash, SRAM and ROM)
      1. 6.3.1  Bit Multiplexing in Flash Memory Array
      2. 6.3.2  Bit Multiplexing in SRAM Memory Array
      3. 6.3.3  Data Scrubbing to Detect/Correct Memory Errors
      4. 6.3.4  Flash ECC
      5. 6.3.5  Flash Program Verify and Erase Verify Check
      6. 6.3.6  Software Test of ECC Logic
      7. 6.3.7  Software Test of Flash Prefetch, Data Cache and Wait-States
      8. 6.3.8  Access Protection Mechanism for Memories
      9. 6.3.9  SRAM ECC
      10. 6.3.10 SRAM Parity
      11. 6.3.11 Software Test of Parity Logic
      12. 6.3.12 Software Test of SRAM
      13. 6.3.13 Memory Power-On Self-Test (MPOST)
      14. 6.3.14 Background CRC
      15. 6.3.15 Watchdog for Background CRC
    4. 6.4 On-Chip Communication Including Bus-Arbitration
      1. 6.4.1  1oo2 Software Voting Using Secondary Free Running Counter
      2. 6.4.2  DMA Overflow Interrupt
      3. 6.4.3  Maintaining Interrupt Handler for Unused Interrupts
      4. 6.4.4  Power-Up Pre-Operational Security Checks
      5. 6.4.5  Majority Voting and Error Detection of Link Pointer
      6. 6.4.6  PIE Double SRAM Hardware Comparison
      7. 6.4.7  PIE Double SRAM Comparison Check
      8. 6.4.8  Software Check of X-BAR Flag
      9. 6.4.9  Software Test of ePIE Operation Including Error Tests
      10. 6.4.10 Disabling of Unused DMA Trigger Sources
      11. 6.4.11 Software Test of CLB Function Including Error Tests
      12. 6.4.12 Monitoring of CLB by eCAP or eQEP
      13. 6.4.13 Periodic Software Read Back of SPI Buffer
      14. 6.4.14 Timeout detection through ERAD counter
    5. 6.5 Digital I/O
      1. 6.5.1  eCAP Application Level Safety Mechanism
      2. 6.5.2  ePWM Application Level Safety Mechanism
      3. 6.5.3  ePWM Fault Detection Using X-BAR
      4. 6.5.4  ePWM Synchronization Check
      5. 6.5.5  eQEP Application Level Safety Mechanism
      6. 6.5.6  eQEP Quadrature Watchdog
      7. 6.5.7  eQEP Software Test of Quadrature Watchdog Functionality
      8. 6.5.8  Hardware Redundancy
      9. 6.5.9  HRPWM Built-In Self-Check and Diagnostic Capabilities
      10. 6.5.10 Information Redundancy Techniques
      11. 6.5.11 Monitoring of ePWM by eCAP
      12. 6.5.12 Monitoring of ePWM by ADC
      13. 6.5.13 Online Monitoring of Periodic Interrupts and Events
      14. 6.5.14 SD Modulator Clock Fail Detection Mechanism
      15. 6.5.15 Software Test of Function Including Error Tests
      16. 6.5.16 Monitoring of HRPWM by HRCAP
      17. 6.5.17 HRCAP Calibration Logic Test Feature
      18. 6.5.18 QMA Error Detection Logic
    6. 6.6 Analog I/O
      1. 6.6.1 ADC Information Redundancy Techniques
      2. 6.6.2 ADC Input Signal Integrity Check
      3. 6.6.3 ADC Signal Quality Check by Varying Acquisition Window
      4. 6.6.4 CMPSS Ramp Generator Functionality Check
      5. 6.6.5 DAC to ADC Loopback Check
      6. 6.6.6 Opens/Shorts Detection Circuit for ADC
      7. 6.6.7 VDAC Conversion by ADC
      8. 6.6.8 Disabling Unused Sources of SOC Inputs to ADC
    7. 6.7 Data Transmission
      1. 6.7.1  Information Redundancy Techniques Including End-to-End Safing
      2. 6.7.2  Bit Error Detection
      3. 6.7.3  CRC in Message
      4. 6.7.4  DCAN Acknowledge Error Detection
      5. 6.7.5  DCAN Form Error Detection
      6. 6.7.6  DCAN Stuff Error Detection
      7. 6.7.7  I2C Access Latency Profiling Using On-Chip Timer
      8. 6.7.8  I2C Data Acknowledge Check
      9. 6.7.9  Parity in Message
      10. 6.7.10 SCI Break Error Detection
      11. 6.7.11 Frame Error Detection
      12. 6.7.12 Overrun Error Detection
      13. 6.7.13 Software Test of Function Using I/O Loopback
      14. 6.7.14 SPI Data Overrun Detection
      15. 6.7.15 Transmission Redundancy
      16. 6.7.16 FSI Data Overrun/Underrun Detection
      17. 6.7.17 FSI Frame Overrun Detection
      18. 6.7.18 FSI CRC Framing Checks
      19. 6.7.19 FSI ECC Framing Checks
      20. 6.7.20 FSI Frame Watchdog
      21. 6.7.21 FSI RX Ping Watchdog
      22. 6.7.22 FSI Tag Monitor
      23. 6.7.23 FSI Frame Type Error Detection
      24. 6.7.24 FSI End of Frame Error Detection
      25. 6.7.25 FSI Register Protection Mechanisms
      26. 6.7.26 LIN Physical Bus Error Detection
      27. 6.7.27 LIN No-Response Error Detection
      28. 6.7.28 LIN Checksum Error Detection
      29. 6.7.29 Data Parity Error Detection
      30. 6.7.30 LIN ID Parity Error Detection
      31. 6.7.31 PMBus Protocol CRC in Message
      32. 6.7.32 Clock Timeout
      33. 6.7.33 Communication Access Latency Profiling Using On-Chip Timer
      34. 6.7.34 Signature mechanism for interrupt and acknowlegdement in software
      35. 6.7.35 Software Timeout mechansim for interrupt logic
      36. 6.7.36 Access protection enable for read/write operations in software
      37. 6.7.37 Detection of illegal access sequences or access types from host to device
      38. 6.7.38 Detection of simultaneous MMR access by host and device
      39. 6.7.39 Enabling locking mechanism for registers
      40. 6.7.40 Disabling of unused EVENTRIG trigger sources
  8. 7References
  9.   A Safety Architecture Configurations
    1.     A.1 Safety Architecture Configurations
  10.   B Distributed Developments
    1.     B.1 How the Functional Safety Lifecycle Applies to Functional Safety-Compliant Products
    2.     B.2 Activities Performed by Texas Instruments
    3.     B.3 Information Provided
  11.   C Summary of Safety Features and Diagnostics
    1.     C.1 Summary of Safety Features and Diagnostics
  12.   D Glossary
    1.     D.1 Glossary

6.5.15 Software Test of Function Including Error Tests

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

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

  • DMA functionality can be checked by transferring a known good data from a source memory to the destination memory and checking for data integrity after the transfer. The transfer can be initiated using the software trigger available (CONTROL.PERINTFRC). On chip timer can be used to profile the time required for such a data transfer.
  • Software test of 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 it at 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 enable (XINTxCR.ENABLE) functionality as well.
  • eCAP, HRCAP 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 and HRCAP, 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 6.3.7.
  • 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 suitable stimulus using ePWM and observing the response using one of the capture (time stamping) modules (eCAP, XINT, eQEP, and so forth). It is recommended to cover the various register values associated with application configuration while performing the software test. Due to the regular linear nature of the various sub-modules, it is possible to get high coverage using a software test.
  • A software test of SRAM wrapper logic should provide diagnostic coverage for arbitration between various masters 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 6.3.12).
  • The interconnect (INC) functionality can be tested by writing complementary data-patterns like 0xA5A5,0x5A5A, and so forth from processing units from CPU, and reading back it from registers of the IPs’ connected via different bridges. The read-back data can be compared with expected golden values to ensure 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.
  • DAC has a set of control registers that can be checked by writing complementary data-patterns like 0xA5A5, 0x5A5A, and so forth in 16-bit access mode. All the registers can be read back and compared to expected values. Registers can be checked for reset feature by configuring the registers to 0xA5A5 pattern, asserting soft reset of DAC, reading back the registers and comparing the read back value with the expected reset value. Lock register can be checked to ensure it is set-once. Also, the registers which are getting locked must not update when written. To test core functionality of the DAC module, it can be configured using software to provide a set of predetermined voltage levels. These voltage levels can be measured by external or internal ADC and results thus obtained can be cross checked against the expected value to ensure proper operation. Extreme corner values of DAC as per application can be programmed and tested to check the successful conversion of digital to analog module across a valid range.
  • 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 can be read back and compared against expected values. These accesses can be covered by applicable masters viz. DMA and CPU. Features of the CMPSS module such as ramp decrement can be checked for counting down of RAMPDLYA after it is loaded from RAMPDLYS by a rising PWMSYNC signal. It should be ensured 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 them to a variety of SAMPWIN (Sample window) and THRESH (Majority voting threshold) values, and then verifying COMPHSTS/COMPLSTS changes with change in filter output. Applicable range of filter clock pre-scaler values (CTRIPLFILCLKCTL) can be exercised to ensure that filter samples correctly.
  • The general operation of the CPU Timers can be tested by a software test by loading 32-bit counter register TIMH from period register PRDH, starts decrementing of the counter on every clock cycle. When counter reaches zero a timer interrupt output generates an interrupt pulse. While testing the timer functionality vary the Timer Prescale Counter (TPR) value and also vary input clocks by selecting clock source as SYSCLK, INTOSC1, INTOSC2, or XTAL. Test interrupts generation capability at the end of the timer counting. 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 ensure that all access other than execute access is blocked.