SPRUI78D March   2019  – January 2022 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1.   Trademarks
  2. 1 Introduction
    1. 1.1 About This Document
    2. 1.2 Acronyms Used in This Document
    3. 1.3 C2000 Architecture and Product Overview
      1. 1.3.1 TMS320F2837xD Delfino MCU
      2. 1.3.2 TMS320F2837xS Delfino MCU
      3. 1.3.3 TMS320F2807x Piccolo MCU
  3. 2 System Integrator Development Interface Agreement
    1. 2.1 Safety Enabled Design Packages for Functional Safety Applications
    2. 2.2 System Integrator Activities
      1. 2.2.1 Operational and Environmental Constraints
      2. 2.2.2 Safety Concept Definition
      3. 2.2.3 Safety Concept Implementation
      4. 2.2.4 Verification of Safety Concept Including Safety Metric Calculation
    3. 2.3 Product Safety Constraints
    4. 2.4 Suggestions for Improving Freedom From Interference
    5. 2.5 Suggestions for Addressing Common Cause Failures
    6. 2.6 Support for System Integrator Activities
  4. 3 C2000 Development Process for Management of Systematic Faults
    1. 3.1 TI's Hardware Development Process
    2. 3.2 Yogitech fRMethodology Enhanced Development Process
    3. 3.3 TI’s Enhanced Safety Development Process
    4. 3.4 C2000 Diagnostics Libraries
      1. 3.4.1 TMS320F2837xD TMS320F2837xS TMS320F2807x Diagnostic Software Library (SDL)
      2. 3.4.2 C2000 CLA STL (CLA-STL)
  5. 4 TMS320F2837xD/S and TMS320F2807x MCU Architecture for Management of Random Faults
    1. 4.1 Functional Safety Concept
      1. 4.1.1 VDA E-GAS Monitoring Concept
      2. 4.1.2 Fault Tolerant Time Interval (FTTI)
    2. 4.2 TMS320F2837xD/S and TMS320F2807x MCU Safety Philosophy
      1. 4.2.1 TMS320F2837xD MCU Safety Philosophy
      2. 4.2.2 TMS320F2837xS and TMS320F2807x MCU Safety Philosophy
      3. 4.2.3 Assumed Safety Requirements
      4. 4.2.4 C2000 MCU Safe State
      5. 4.2.5 Operating States
      6. 4.2.6 Management of Faults
  6. 5 Brief Description of Safety Elements
    1. 5.1 C2000 MCU Infrastructure Components
      1. 5.1.1 Power Supply
      2. 5.1.2 Clock
      3. 5.1.3 Reset
      4. 5.1.4 System Control Module and Configuration Registers
      5. 5.1.5 Efuse Static Configuration
      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)
      2. 5.2.2 Control Law Accelerator
    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 Direct Memory Access (DMA)
      3. 5.4.3 Inter Processor Communication (IPC)
      4. 5.4.4 Enhanced Peripheral Interrupt Expander (ePIE) Module
      5. 5.4.5 Dual Zone Code Security Module (DCSM)
      6. 5.4.6 CrossBar (X-BAR)
      7. 5.4.7 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 Sigma Delta Filter Module (SDFM)
      7. 5.5.7 External Interrupt (XINT)
    6. 5.6 Analogue I/O
      1. 5.6.1 Analog-to-Digital Converter (ADC)
      2. 5.6.2 Buffered Digital to Analog Converter (DAC)
      3. 5.6.3 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 Multi-Channel Buffered Serial Port (MCBSP)
      6. 5.7.6 External Memory Interface (EMIF)
    8. 5.8 Not Safety Related Elements
  7. 6 Brief Description of Diagnostics
    1. 6.1 C2000 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  EALLOW and MEALLOW Protection for Critical Registers
      4. 6.1.4  Efuse Autoload Self-Test
      5. 6.1.5  Efuse ECC
      6. 6.1.6  Efuse ECC Logic Self-Test
      7. 6.1.7  External Clock Monitoring via XCLKOUT
      8. 6.1.8  External Monitoring of Warm Reset (XRSn)
      9. 6.1.9  External Voltage Supervisor
      10. 6.1.10 External Watchdog
      11. 6.1.11 Glitch Filtering on Reset Pins
      12. 6.1.12 Hardware Disable of JTAG Port
      13. 6.1.13 Internal Watchdog (WD)
      14. 6.1.14 Lock Mechanism for Control Registers
      15. 6.1.15 Missing Clock Detect (MCD)
      16. 6.1.16 NMIWD Reset Functionality
      17. 6.1.17 NMIWD Shadow Registers
      18. 6.1.18 Multi-Bit Enable Keys for Control Registers
      19. 6.1.19 Online Monitoring of Temperature
      20. 6.1.20 Periodic Software Read Back of Static Configuration Registers
      21. 6.1.21 Peripheral Clock Gating (PCLKCR)
      22. 6.1.22 Peripheral Soft Reset (SOFTPRES)
      23. 6.1.23 PLL Lock Profiling Using On-Chip Timer
      24. 6.1.24 Reset Cause Information
      25. 6.1.25 Software Read Back of Written Configuration
      26. 6.1.26 Software Test of ERRORSTS Functionality
      27. 6.1.27 Software Test of Missing Clock Detect Functionality
      28. 6.1.28 Software Test of Reset
      29. 6.1.29 Software Test of Watchdog(WD) Operation
    2. 6.2 Processing Elements
      1. 6.2.1  CLA Handling of Illegal Operation and Illegal Results
      2. 6.2.2  CLA Liveness Check Using CPU
      3. 6.2.3  CPU Hardware Built-In Self-Test (HWBIST)
      4. 6.2.4  CPU Hardware Built-In Self-Test (HWBIST) Auto-Coverage
      5. 6.2.5  CPU Hardware Built-In Self-Test (HWBIST) Fault Injection Capability
      6. 6.2.6  CPU Hardware Built-In Self-Test (HWBIST) Timeout Feature
      7. 6.2.7  CPU Handling of Illegal Operation, Illegal Results and Instruction Trapping
      8. 6.2.8  Reciprocal Comparison by Software
      9. 6.2.9  Software Test of CLA
      10. 6.2.10 Stack Overflow Detection
      11. 6.2.11 VCU CRC Check of Static Memory Contents
      12. 6.2.12 VCU CRC Auto Coverage
      13. 6.2.13 Disabling of Unused CLA Task Trigger Sources
    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
    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  Event Timestamping Using IPC Counter
      4. 6.4.4  Maintaining Interrupt Handler for Unused Interrupts
      5. 6.4.5  Majority Voting and Error Detection of Link Pointer
      6. 6.4.6  PIE Double SRAM Comparison Check
      7. 6.4.7  PIE Double SRAM Hardware Comparison
      8. 6.4.8  Power-Up Pre-Operational Security Checks
      9. 6.4.9  Software Check of X-BAR Flag
      10. 6.4.10 Software Test of ePIE Operation Including Error Tests
      11. 6.4.11 Disabling of Unused DMA Trigger Sources
      12. 6.4.12 IPC 64-Bit Counter Value Plausibility Check
    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 XBAR
      4. 6.5.4  ePWM Synchronization Check
      5. 6.5.5  eQEP Application Level Safety Mechanisms
      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 Interrupts and Events
      14. 6.5.14 SDFM Comparator Filter for Online Monitoring
      15. 6.5.15 SD Modulator Clock Fail Detection Mechanism
      16. 6.5.16 Software Test of Function Including Error Tests
    6. 6.6 Analogue 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 DAC to Comparator Loopback Check
      7. 6.6.7 Opens/Shorts Detection Circuit for ADC
      8. 6.6.8 VDAC Conversion by ADC
      9. 6.6.9 Disabling Unused Sources of SOC Inputs to ADC
    7. 6.7 Data Transmission
      1. 6.7.1  Bit Error Detection
      2. 6.7.2  CRC in Message
      3. 6.7.3  DCAN Acknowledge Error Detection
      4. 6.7.4  DCAN Form Error Detection
      5. 6.7.5  DCAN Stuff Error Detection
      6. 6.7.6  EMIF Access Latency Profiling Using On-Chip Timer
      7. 6.7.7  EMIF Access Protection Mechanism
      8. 6.7.8  EMIF Asynchronous Memory Timeout Protection Mechanism
      9. 6.7.9  I2C Access Latency Profiling Using On-Chip Timer
      10. 6.7.10 Information Redundancy Techniques Including End-to-End Safeing
      11. 6.7.11 I2C Data Acknowledge Check
      12. 6.7.12 McBSP Receiver Overrun Detection
      13. 6.7.13 McBSP Receiver Sync Error Detection
      14. 6.7.14 McBSP Transmitter Sync Error Detection
      15. 6.7.15 McBSP Transmitter Underflow Detection
      16. 6.7.16 Parity in Message
      17. 6.7.17 SCI Break Error Detection
      18. 6.7.18 SCI Frame Error Detection
      19. 6.7.19 SCI Overrun Error Detection
      20. 6.7.20 Software Test of Function Using I/O Loopback
      21. 6.7.21 SPI Data Overrun Detection
      22. 6.7.22 Transmission Redundancy
  8. 7 Safety Architecture Configurations
  9. 8 Terms and Definitions
  10. 9 Summary of Safety Features and Diagnostics
  11. 10References
  12. 11Revision History

4.2.2 TMS320F2837xS and TMS320F2807x MCU Safety Philosophy

TMS320F2837xS and TMS320F2807x class of devices have a single CPU subsystem. The CPU subsystem has a pair of diverse processing units (C28x and CLA) with different hardware architecture, instruction set and software tools. Any of the two processing units can be used to execute main function (Level 1 of VDA E-gas concept).

The second processing unit of the CPU subsystem can be used for implementing Level 2 monitoring as illustrated in Figure 4-6. Due to diversity of the processing units, a 1oo1D architecture can be implemented using “reciprocal comparison by software in separate processing units” providing high diagnostic coverage for the processing units (ISO 26262-5, Table D.4 and IEC 61508-2, Table A.4). Heterogeneous CPU cores minimize possibility of common mode failures while implementing this reciprocal comparison thereby improving confidence in its Diagnostic Coverage. This implementation will have a single independent processing channel for TMS320F2837xS.

The product safety philosophy is explained based on 1oo1D safety configuration implemented using reciprocal comparison and other hardware diagnostics. Figure 4-8 illustrates safety partitioning based on the diagnostics employed. The various layers implemented are:

  • Reciprocal Comparison Layer (RED) – This is the region of logic used for all processing operations. This logic has a one processing unit executing the main functionality (Level 1), second processing unit with specific assumptions of use and other hardware diagnostic elements executing monitoring functionality (Level 2). The memories closely coupled with C28x and CLA are protected with either ECC or parity. This region with high diagnostic coverage for both single point faults and latent faults can be used for performing software diagnostic on other design elements. The diverse processing (C28x and CLA) have different hardware architecture, instruction set and software tools. However, they share common power, clock, reset, bus and infrastructure elements. System integrator needs to independently perform common cause failure analysis and freedom from interference analysis and implement the necessary safety measures (for example, External Watchdog, Access Protection Mechanism for Memories, and so forth) to address the concerns which may come up from the analysis.
  • Blended Layer (BLACK) – This is the region of logic that includes safety critical peripherals. This region has a mix of (predominantly) software and hardware diagnostics. Application protocols (for example, end-to-end Safeing techniques used in communication protocols) and application related checks (for example, measured values falls within the safe operating limit) are used to support functionally safe operation.
  • Offline Layer (BLUE) – This region of logic has very limited or no integrated hardware diagnostics. Many features in this layer (for example, debug, test, calibration functions, and so forth) are used for production test or application debug and not used during regular operation. Techniques are employed to avoid freedom from interference to main application by the logic elements in this layer.

Due to the inherent versatility of the device architecture, several software voting based safety configurations are possible. Some of the safety configurations possible with TMS320F2837xD for improving diagnostic coverage are explained in Table 7-1. While implementing these configurations, system integrator needs to consider the potential common mode failures and address them in an appropriate manner. This may suitably be modified to adapt to TMS320F2837xS and TMS320F2807x requirements based on the availability of processing units. (As stated earlier, the device claims no hardware fault tolerance, (for example, no claims of HFT > 0), as defined in IEC 61508:2010).

GUID-57F89391-3354-4B83-B49E-C2F4D6D37058-low.png Figure 4-7 C2000 MCU Delfino F2837xD With Safety Features
GUID-44C05925-5F77-4710-A679-1E05776CA39B-low.gif Figure 4-8 C2000 MCU Delfino F2837xD Device Block Diagram With Safety Partitioning