SWRU626 December   2025 CC3501E , CC3551E

 

  1.   1
  2. 1 Read This First
    1. 1.1 About This Manual
    2. 1.2 Register, Field, and Bit Calls
    3.     Trademarks
  3. 2 Architecture Overview
    1. 2.1  Target Applications
    2. 2.2  Introduction
    3. 2.3  Internal System Diagram
    4. 2.4  Arm Cortex M33
      1. 2.4.1 Processor Core
      2. 2.4.2 SysTick Timer
      3. 2.4.3 Nested Vectored Interrupt Controller
      4. 2.4.4 System Control Block (SCB)
      5. 2.4.5 TI AI instruction extensions
    5. 2.5  Power Management
      1. 2.5.1 VDD_MAIN
      2. 2.5.2 VDD_IO
      3. 2.5.3 VDDSF
      4. 2.5.4 VDD_PA
    6. 2.6  Debug Subsystem (DEBUGSS)
    7. 2.7  Memory Subsystem (MEMSS)
      1. 2.7.1 External Memory Interface
    8. 2.8  Hardware Security Module
    9. 2.9  General Purpose Timers (GPT)
    10. 2.10 Real Time Clock (RTC)
    11. 2.11 Direct Memory Access
    12. 2.12 GPIOs
    13. 2.13 Communication Peripherals
      1. 2.13.1 UART
      2. 2.13.2 I2C
      3. 2.13.3 SPI
      4. 2.13.4 I2S
      5. 2.13.5 SDMMC
      6. 2.13.6 SDIO
      7. 2.13.7 CAN
      8. 2.13.8 ADC
  4. 3  Arm Cortex-M33 Processor
    1. 3.1 Arm Cortex-M33 Processor Introduction
    2. 3.2 Block Diagram
    3. 3.3 M33 instantiation parameters
    4. 3.4 Arm Cortex-M33 System Peripheral Details
      1. 3.4.1 Floating Point Unit (FPU)
      2. 3.4.2 Memory Protection Unit (MPU)
      3. 3.4.3 Digital Signal Processing (DSP)
      4. 3.4.4 Security Attribution Unit (SAU)
      5. 3.4.5 System Timer
      6. 3.4.6 Nested Vectored Interrupt Controller
      7. 3.4.7 System Control Block
      8. 3.4.8 System Control Space
    5. 3.5 CPU Sub-System Peripheral Details
      1. 3.5.1 Trace Port Interface Unit (TPIU)
      2. 3.5.2 DAP Bridge and Debug Authentication
      3. 3.5.3 Implementation Defined Attribution Unit (IDAU)
    6. 3.6 Programming Model
      1. 3.6.1 Modes of operation and execution
        1. 3.6.1.1 Security states
        2. 3.6.1.2 Operating modes
        3. 3.6.1.3 Operating states
        4. 3.6.1.4 Privileged access and unprivileged user access
      2. 3.6.2 Instruction set summary
      3. 3.6.3 Memory model
        1. 3.6.3.1 Private Peripheral Bus
        2. 3.6.3.2 Unaligned accesses
      4. 3.6.4 Processor core registers summary
      5. 3.6.5 Exceptions
        1. 3.6.5.1 Exception handling and prioritization
    7. 3.7 TrustZone-M
      1. 3.7.1 Overview
      2. 3.7.2 M33 Configuration
      3. 3.7.3 Description of elements
        1. 3.7.3.1 IDAU (Implementation Defined Attribution Unit)
          1. 3.7.3.1.1 Expected use
    8. 3.8 CC35xx Host MCU Registers
      1. 3.8.1 HOSTMCU_AON Registers
      2. 3.8.2 HOST_MCU Registers
      3. 3.8.3 HOST_MCU_SEC Registers
    9. 3.9 Arm® Cortex®-M33 Registers
      1. 3.9.1  CPU_ROM_TABLE Registers
      2. 3.9.2  TPIU Registers
      3. 3.9.3  DCB Registers
      4. 3.9.4  DIB Registers
      5. 3.9.5  DWT Registers
      6. 3.9.6  FPB Registers
      7. 3.9.7  FPE Registers
      8. 3.9.8  ICB Registers
      9. 3.9.9  ITM Registers
      10. 3.9.10 MPU Registers
      11. 3.9.11 NVIC Registers
      12. 3.9.12 SAU Registers
      13. 3.9.13 SCB Registers
      14. 3.9.14 SYSTIMER Registers
      15. 3.9.15 SYSTICK Registers
  5. 4 Memory Map
    1. 4.1 Memory Map
  6. 5 Interrupts and Events
    1. 5.1 Exception Model
      1. 5.1.1 Exception States
      2. 5.1.2 Exception Types
      3. 5.1.3 Exception Handlers
      4. 5.1.4 Vector Table
      5. 5.1.5 Exception Priorities
      6. 5.1.6 Interrupt Priority Grouping
      7. 5.1.7 Exception Entry and Return
        1. 5.1.7.1 Exception Entry
        2. 5.1.7.2 Exception Return
    2. 5.2 Fault Handling
      1. 5.2.1 Fault Types
      2. 5.2.2 Fault Escalation to HardFault
      3. 5.2.3 Fault Status Registers and Fault Address Registers
      4. 5.2.4 Lockup
    3. 5.3 Security State Switches
    4. 5.4 Event Manager
      1. 5.4.1 Introduction
      2. 5.4.2 Interrupts List
      3. 5.4.3 Wakeup Sources
      4. 5.4.4 Shared Peripherals MUX Selector
        1. 5.4.4.1 ADC HW Event Selector Mux
        2. 5.4.4.2 I2S HW Event Selector Mux
        3. 5.4.4.3 PDM HW Event Selector Mux
      5. 5.4.5 Timers MUX Selector Mux
        1. 5.4.5.1 SysTimer0 HW Event Selector Mux
        2. 5.4.5.2 SysTimer1 HW Event Selector Mux
        3. 5.4.5.3 RTC HW Event Selector Mux
      6. 5.4.6 GPTIMERs MUX Selector Mux
        1. 5.4.6.1 GPTIMER0 HW Event Selector Mux
        2. 5.4.6.2 GPTIMER1 HW Event Selector Mux
    5. 5.5 SOC_IC Registers
    6. 5.6 SOC_AON Registers
    7. 5.7 SOC_AAON Registers
  7. 6 Debug Subsystem (DEBUGSS)
    1. 6.1 Introduction
    2. 6.2 Block Diagram
    3. 6.3 Overview
    4. 6.4 Physical Interface
    5. 6.5 Debug Access Ports
    6. 6.6 Debug Features
      1. 6.6.1 Processor Debug
      2. 6.6.2 Breakpoint Unit (BPU)
      3. 6.6.3 Peripheral Debug
    7. 6.7 Behavior in Low Power Modes
    8. 6.8 Debug Access Control
    9. 6.9 SOC_DEBUGSS Registers
  8. 7 Power, Reset, Clock Management
    1. 7.1 Power Management
      1. 7.1.1 Power Supply System
        1. 7.1.1.1 VDD_MAIN
        2. 7.1.1.2 VIO
        3. 7.1.1.3 VDDSF
        4. 7.1.1.4 VPA
      2. 7.1.2 Power States
      3. 7.1.3 Power Domains
      4. 7.1.4 Brownout (BOR)
      5. 7.1.5 Boot Sequence
    2. 7.2 Reset
      1. 7.2.1 Reset Cause
      2. 7.2.2 Watchdog Timer (WDT)
    3. 7.3 Clocks
      1. 7.3.1 Fast Clock
      2. 7.3.2 Slow Clock
        1. 7.3.2.1 Slow Clock Overview
        2. 7.3.2.2 Slow Clock Tree
        3. 7.3.2.3 Slow Clock Boot Process
    4. 7.4 PRCM_AON Registers
    5. 7.5 PRCM_SCRATCHPAD Registers
  9. 8 Memory Subsystem (MEMSS)
    1. 8.1  Introduction
    2. 8.2  SRAM
    3. 8.3  D-Cache
    4. 8.4  Flash
    5. 8.5  PSRAM
    6. 8.6  XiP Memory Access
      1. 8.6.1 OTFDE
      2. 8.6.2 xSPI
      3. 8.6.3 Topology
      4. 8.6.4 µDMA
      5. 8.6.5 Arbiter
    7. 8.7  ICACHE Registers
    8. 8.8  DCACHE Registers
    9. 8.9  OSPI Registers
    10. 8.10 HOST_XIP Registers
  10. 9 Hardware Security Module (HSM)
    1. 9.1 Introduction
    2. 9.2 Overview
    3. 9.3 Mailbox and Register Access Firewall
    4. 9.4 DMA Firewall
    5. 9.5 HSM Key Storage
    6. 9.6 HSM Registers
    7. 9.7 HSM_NON_SEC Registers
    8. 9.8 HSM_SEC Registers
  11. 10Device Boot and Bootloader
    1. 10.1 CC35xx Boot Concept
    2. 10.2 Features
    3. 10.3 Vendor Images Format and Processing
      1. 10.3.1 External Flash Arrangement
      2. 10.3.2 Vendor Images Format
    4. 10.4 Boot Flows
      1. 10.4.1 Application Execution Boot Flow
      2. 10.4.2 Activation Flow
      3. 10.4.3 Initial Programming Flow
      4. 10.4.4 Reprogramming Flow
      5. 10.4.5 Wireless Connectivity Testing Tool Flow
    5. 10.5 Chain of Trust
  12. 11Direct Memory Access (DMA)
    1. 11.1 Overview
    2. 11.2 Block Diagram
    3. 11.3 Functional Description
      1. 11.3.1 Channels Assignment
      2. 11.3.2 Transfer Types
      3. 11.3.3 Addressing Modes
      4. 11.3.4 Transfer Modes
      5. 11.3.5 DMA Aligner Support
      6. 11.3.6 Initiating DMA Transfers
      7. 11.3.7 Stopping DMA Transfers
      8. 11.3.8 Channel Priorities
      9. 11.3.9 DMA Interrupts
    4. 11.4 HOST_DMA Registers
  13. 12One Time Programming (OTP)
  14. 13General Purpose Timers (GPT)
    1. 13.1 Overview
    2. 13.2 Block Diagram
    3. 13.3 Functional Description
      1. 13.3.1  Prescaler
      2. 13.3.2  Counter
      3. 13.3.3  Target
      4. 13.3.4  Channel Input Logic
      5. 13.3.5  Channel Output Logic
      6. 13.3.6  Channel Actions
        1. 13.3.6.1 Period and Pulse Width Measurement
        2. 13.3.6.2 Clear on Zero, Toggle on Compare Repeatedly
        3. 13.3.6.3 Set on Zero, Toggle on Compare Repeatedly
      7. 13.3.7  Channel Capture Configuration
      8. 13.3.8  Channel Filters
        1. 13.3.8.1 Setting up the Channel Filters
      9. 13.3.9  Synchronize Multiple GPTimers
      10. 13.3.10 Interrupts, ADC Trigger, and DMA Request
    4. 13.4 Timer Modes
      1. 13.4.1 Quadrature Decoder
      2. 13.4.2 DMA
      3. 13.4.3 IR Generation
      4. 13.4.4 Fault and Park
      5. 13.4.5 Dead-Band
      6. 13.4.6 Dead-Band, Fault and Park
      7. 13.4.7 Example Application: Brushless DC (BLDC) Motor
    5. 13.5 GPTIMER Registers
  15. 14System Timer (SysTimer)
    1. 14.1 Overview
    2. 14.2 Block Diagram
    3. 14.3 Functional Description
      1. 14.3.1 Common Channel Features
        1. 14.3.1.1 Compare Mode
        2. 14.3.1.2 Capture Mode
        3. 14.3.1.3 Additional Channel Arming Methods
      2. 14.3.2 Interrupts and Events
    4. 14.4 SYSRESOURCES Registers
    5. 14.5 SYSTIM Registers
  16. 15Real-Time Clock (RTC)
    1. 15.1 Introduction
    2. 15.2 Block Diagram
    3. 15.3 Interrupts and Events
      1. 15.3.1 Input Event
      2. 15.3.2 Output Event
      3. 15.3.3 Arming and Disarming Channels
    4. 15.4 CAPTURE and COMPARE Configurations
      1. 15.4.1 CHANNEL 0 - COMPARE CHANNEL
      2. 15.4.2 CHANNEL 1 - CAPTURE CHANNEL
    5. 15.5 RTC Registers
  17. 16General Purpose Input/Output (GPIOs)
    1. 16.1 Introduction
    2. 16.2 Block Diagram
    3. 16.3 I/O Mapping and Configuration
      1. 16.3.1 Basic I/O Mapping
      2. 16.3.2 Pin Mapping
    4. 16.4 Edge Detection
    5. 16.5 GPIO
    6. 16.6 I/O Pins
    7. 16.7 Unused Pins
    8. 16.8 IOMUX Registers
  18. 17Universal Asynchronous Receivers/Transmitters (UART)
    1. 17.1 Introduction
    2. 17.2 Block Diagram
    3. 17.3 UART Functional Description
      1. 17.3.1 Transmit and Receive Logic
      2. 17.3.2 Baud Rate Generation
      3. 17.3.3 FIFO Operation
        1. 17.3.3.1 FIFO Remapping
      4. 17.3.4 Data Transmission
      5. 17.3.5 Flow Control
      6. 17.3.6 IrDA Encoding and Decoding
      7. 17.3.7 Interrupts
      8. 17.3.8 Loopback Operation
    4. 17.4 UART-LIN Specification
      1. 17.4.1 Break transmission in UART mode
      2. 17.4.2 Break reception in UART mode
      3. 17.4.3 Break/Synch transmission in LIN mode
      4. 17.4.4 Break/Synch reception in LIN mode
      5. 17.4.5 Dormant mode operation
      6. 17.4.6 Event signal generation
      7. 17.4.7 Event signal detection when device is in active/idle modes
      8. 17.4.8 Event signal detection when device is in sleep mode
    5. 17.5 Interface to Host DMA
    6. 17.6 Initialization and Configuration
    7. 17.7 UART Registers
  19. 18Serial Peripheral Interface (SPI)
    1. 18.1 Overview
      1. 18.1.1 Features
      2. 18.1.2 Block Diagram
    2. 18.2 Signal Description
    3. 18.3 Functional Description
      1. 18.3.1  Clock Control
      2. 18.3.2  FIFO Operation
        1. 18.3.2.1 Transmit FIFO
        2. 18.3.2.2 Repeated Transmit Operation
        3. 18.3.2.3 Receive FIFO
        4. 18.3.2.4 FIFO Flush
      3. 18.3.3  Interrupts
      4. 18.3.4  Data Format
      5. 18.3.5  Delayed Data Sampling
      6. 18.3.6  Chip Select Control
      7. 18.3.7  Command Data Control
      8. 18.3.8  Protocol Descriptions
        1. 18.3.8.1 Motorola SPI Frame Format
        2. 18.3.8.2 Texas Instruments Synchronous Serial Frame Format
        3. 18.3.8.3 MICROWIRE Frame Format
      9. 18.3.9  CRC Configuration
      10. 18.3.10 Auto CRC Functionality
      11. 18.3.11 SPI Status
      12. 18.3.12 Debug Halt
    4. 18.4 Host DMA Operation
    5. 18.5 Initialization and Configuration
    6. 18.6 SPI Registers
  20. 19Inter-Integrated Circuit (I2C) Interface
    1. 19.1 Introduction
    2. 19.2 Block Diagram
    3. 19.3 Functional Description
      1. 19.3.1 Clock Control
        1. 19.3.1.1 Internal Clock
        2. 19.3.1.2 External Clock
      2. 19.3.2 General Architecture
        1. 19.3.2.1  Start and Stop Conditions
        2. 19.3.2.2  Data Format with 7-Bit Address
        3. 19.3.2.3  Data Format with 10-Bit Addressing
          1. 19.3.2.3.1 Additional 10-Bit Scenarios
        4. 19.3.2.4  Acknowledge
        5. 19.3.2.5  Repeated Start
        6. 19.3.2.6  Clock Stretching
        7. 19.3.2.7  Arbitration
        8. 19.3.2.8  Multi-Controller mode
        9. 19.3.2.9  Glitch Suppression
        10. 19.3.2.10 FIFO Operation
        11. 19.3.2.11 Burst Mode Operation
        12. 19.3.2.12 DMA Operation
        13. 19.3.2.13 Flush Stale Tx Data in Target Mode
          1. 19.3.2.13.1 Recommended Sequence
        14. 19.3.2.14 SMBUS 3.0 Support
          1. 19.3.2.14.1 Quick Command
          2. 19.3.2.14.2 Acknowledge Control
          3. 19.3.2.14.3 Alert Response protocol
          4. 19.3.2.14.4 Address Resolution Protocol
          5. 19.3.2.14.5 Enhanced Acknowledge Control
    4. 19.4 Initialization and Configuration
    5. 19.5 Interrupts
    6. 19.6 I2C Registers
  21. 20Secure Digital Multimedia Card (SDMMC)
    1. 20.1 Introduction
      1. 20.1.1 SDMMC Features
      2. 20.1.2 Integration
    2. 20.2 Functional Description
      1. 20.2.1  SDMMC Functional Modes
        1. 20.2.1.1 SDMMC Connected to an SD Card
        2. 20.2.1.2 Protocol and Data Format
          1. 20.2.1.2.1 Protocol
          2. 20.2.1.2.2 Data Format
      2. 20.2.2  SD Card Feedback
      3. 20.2.3  Resets
        1. 20.2.3.1 Hardware Reset
        2. 20.2.3.2 Software Reset
      4. 20.2.4  Interrupt Requests
        1. 20.2.4.1 Interrupt-Driven Operation
        2. 20.2.4.2 Polling
      5. 20.2.5  DMA Modes
        1. 20.2.5.1 DMA Peripheral Mode Operations
          1. 20.2.5.1.1 DMA Receive Mode
          2. 20.2.5.1.2 DMA Transmit Mode
      6. 20.2.6  Buffer Management
        1. 20.2.6.1 Data Buffer
          1. 20.2.6.1.1 Memory Size and Block Length
          2. 20.2.6.1.2 Data Buffer Status
      7. 20.2.7  Transfer Process
        1. 20.2.7.1 Different Types of Commands
        2. 20.2.7.2 Different Types of Responses
      8. 20.2.8  Transfer or Command Status and Error Reporting
        1. 20.2.8.1 Busy Timeout for R1b, R5b Response Type
        2. 20.2.8.2 Busy Timeout After Write CRC Status
        3. 20.2.8.3 Write CRC Status Timeout
        4. 20.2.8.4 Read Data Timeout
      9. 20.2.9  Auto Command 12 Timings
        1. 20.2.9.1 Auto Command 12 Timings During Write Transfer
        2. 20.2.9.2 Auto Command 12 Timings During Read Transfer
      10. 20.2.10 Transfer Stop
      11. 20.2.11 Output Signals Generation
        1. 20.2.11.1 Generation on Falling Edge of SDMMC Clock
        2. 20.2.11.2 Generation on Rising Edge of SDMMC Clock
      12. 20.2.12 Test Registers
      13. 20.2.13 SDMMC Hardware Status Features
    3. 20.3 Low-Level Programming Models
      1. 20.3.1 SDMMC Initialization Flow
        1. 20.3.1.1 Enable OCP and CLKADPI Clocks
        2. 20.3.1.2 SD Soft Reset Flow
        3. 20.3.1.3 Set SD Default Capabilities
        4. 20.3.1.4 SDMMC Host and Bus Configuration
      2. 20.3.2 Operational Modes Configuration
        1. 20.3.2.1 Basic Operations for SDMMC
        2. 20.3.2.2 Card Detection, Identification, and Selection
    4. 20.4 SDMMC Registers
  22. 21Secure Digital Input/Output (SDIO)
    1. 21.1 Introduction
    2. 21.2 Block Diagram
    3. 21.3 Functional Description
      1. 21.3.1 SDIO Interface Description
      2. 21.3.2 Protocol and Data Format
      3. 21.3.3 I/O Read/Write Command
        1. 21.3.3.1 IO_WR_DIRECT Command (CMD52)
        2. 21.3.3.2 IO_WR_EXTENDED Command (CMD53)
      4. 21.3.4 Reset
      5. 21.3.5 FIFO Operation
        1. 21.3.5.1 Rx FIFO (For Host Write)
        2. 21.3.5.2 Tx FIFO (For Host Read)
      6. 21.3.6 Interrupt Request
        1. 21.3.6.1 External Host IRQ
        2. 21.3.6.2 M33 IRQ
      7. 21.3.7 Transaction Details
        1. 21.3.7.1 Host write to SDIO IP (Rx FIFO)
          1. 21.3.7.1.1 Host write to SDIO IP (Rx FIFO) – Long SW latency case
          2. 21.3.7.1.2 Host write to SDIO IP (Rx FIFO) – CRC Error Case
        2. 21.3.7.2 Host reads from SDIO (TX buffer)
    4. 21.4 SDIO_CORE Registers
    5. 21.5 SDIO_CARD_FN1 Registers
  23. 22Inter-Integrated Circuit Sound (I2S)
    1. 22.1  Introduction
    2. 22.2  Block Diagram
    3. 22.3  Signal Descriptions
    4. 22.4  Functional Description
      1. 22.4.1 Pin Configuration
      2. 22.4.2 Serial Format Configuration
        1. 22.4.2.1 Register Configuration
      3. 22.4.3 Left-Justified (LJF)
        1. 22.4.3.1 Register Configuration
      4. 22.4.4 Right-Justified (RJF)
        1. 22.4.4.1 Register Configuration
      5. 22.4.5 DSP
        1. 22.4.5.1 Register Configuration
      6. 22.4.6 Clock Configuration
    5. 22.5  Memory Interface
      1. 22.5.1 Sample Word Length
      2. 22.5.2 Padding Mechanism
      3. 22.5.3 Channel Mapping
      4. 22.5.4 Sample Storage in Memory
      5. 22.5.5 DMA Operation
        1. 22.5.5.1 Start-Up
        2. 22.5.5.2 Operation
        3. 22.5.5.3 Shutdown
    6. 22.6  Samplestamp Generator
      1. 22.6.1 Samplestamp Counters
      2. 22.6.2 Start-Up Triggers
      3. 22.6.3 Samplestamp Capture
      4. 22.6.4 Achieving constant audio latency
    7. 22.7  Error Detection
    8. 22.8  Usage
      1. 22.8.1 Start-Up Sequence
      2. 22.8.2 Shutdown Sequence
    9. 22.9  I2S Configuration Guideline
    10. 22.10 I2S Registers
  24. 23Pulse Density Modulation (PDM)
    1. 23.1  Introduction
    2. 23.2  Block Diagram
    3. 23.3  Input Selection
      1. 23.3.1 PDM Data Mode
      2. 23.3.2 Manchester Input Mode
    4. 23.4  CIC Filter
      1. 23.4.1 Filter Design
      2. 23.4.2 Digital Filter Output
      3. 23.4.3 Offset Binary Mode
      4. 23.4.4 Twos-Complement Mode
    5. 23.5  FIFO Organization in Different Modes
      1. 23.5.1 Single Mono Microphone Configuration
        1. 23.5.1.1 24-bit Sample Size
          1. 23.5.1.1.1 32-bit Data Read
        2. 23.5.1.2 16-bit Sample Size
          1. 23.5.1.2.1 32-bit Data Read
          2. 23.5.1.2.2 16-bit Data Read
        3. 23.5.1.3 8-bit Sample Size
          1. 23.5.1.3.1 32-bit Data Read
          2. 23.5.1.3.2 16-bit Data Read
          3. 23.5.1.3.3 8-bit Data Read
      2. 23.5.2 Stereo or Dual Mono Microphone Configuration
        1. 23.5.2.1 24-bit Sample Size
          1. 23.5.2.1.1 32-bit Data Read
        2. 23.5.2.2 16-bit Sample Size
          1. 23.5.2.2.1 32-bit Data Read
          2. 23.5.2.2.2 16-bit Data Read
        3. 23.5.2.3 8-bit Sample Size
          1. 23.5.2.3.1 32-bit Data Read
          2. 23.5.2.3.2 16-bit Data Read
          3. 23.5.2.3.3 8-bit Data Read
      3. 23.5.3 FIFO Threshold Setting
      4. 23.5.4 Reset FIFO
    6. 23.6  Automatic Gain Control (AGC)
      1. 23.6.1 Operation in 2's Complement Format
      2. 23.6.2 Operation in Offset Binary Format
    7. 23.7  Interrupts
    8. 23.8  Clock Select and Control
    9. 23.9  DMA Operation
    10. 23.10 Samplestamp Generator
      1. 23.10.1 Samplestamp Counters
      2. 23.10.2 Start-Up Triggers
      3. 23.10.3 Samplestamp Capture
      4. 23.10.4 Achieving Constant Audio Latency
    11. 23.11 Debug‑Mode Flag Behavior
    12. 23.12 Software Guidelines
    13. 23.13 PDM Registers
  25. 24Analog to Digital Converter (ADC)
    1. 24.1 Overview
    2. 24.2 Block Diagram
    3. 24.3 Functional Description
      1. 24.3.1  ADC Core
      2. 24.3.2  Voltage Reference Options
      3. 24.3.3  Internal Channels
      4. 24.3.4  Resolution Modes
      5. 24.3.5  ADC Clocking
      6. 24.3.6  Power Down Behavior
      7. 24.3.7  Sampling Trigger Sources and Sampling Modes
        1. 24.3.7.1 AUTO Sampling Mode
        2. 24.3.7.2 MANUAL Sampling Mode
      8. 24.3.8  Sampling Period
      9. 24.3.9  Conversion Modes
      10. 24.3.10 ADC Data Format
      11. 24.3.11 Status Register
      12. 24.3.12 ADC Events
        1. 24.3.12.1 Generic Event Publishers (INT_EVENT0 & INT_EVENT1)
        2. 24.3.12.2 DMA Trigger Event Publisher (INT_EVENT2)
        3. 24.3.12.3 Generic Event Subscriber
      13. 24.3.13 Advanced Features
        1. 24.3.13.1 Window Comparator
        2. 24.3.13.2 DMA & FIFO Operation
          1. 24.3.13.2.1 DMA/CPU Operation in Non-FIFO Mode (FIFOEN=0)
          2. 24.3.13.2.2 DMA/CPU Operation in FIFO Mode (FIFOEN=1)
          3. 24.3.13.2.3 DMA/CPU Operation Summary Matrix
        3. 24.3.13.3 Ad-hoc Single Conversion
    4. 24.4 ADC Registers
  26. 25Controller Area Network (CAN)
    1. 25.1 Introduction
    2. 25.2 Functions
    3. 25.3 DCAN Subsystem
    4. 25.4 DCAN Functional Description
      1. 25.4.1 Operating Modes
        1. 25.4.1.1 Software Initialization
        2. 25.4.1.2 Normal Operation
        3. 25.4.1.3 Restricted Operation Mode
        4. 25.4.1.4 Bus Monitoring Mode
        5. 25.4.1.5 Disabled Automatic Retransmission
          1. 25.4.1.5.1 Frame Transmission in DAR Mode
        6. 25.4.1.6 Power Down (Sleep Mode)
          1. 25.4.1.6.1 DCAN clock stop and wake operations
          2. 25.4.1.6.2 DCAN debug suspend operation
        7. 25.4.1.7 Test Modes
          1. 25.4.1.7.1 External Loop Back Mode
          2. 25.4.1.7.2 Internal Loop Back Mode
      2. 25.4.2 Timestamp Generation
        1. 25.4.2.1 Block Diagram
      3. 25.4.3 Timeout Counter
      4. 25.4.4 Rx Handling
        1. 25.4.4.1 Acceptance Filtering
          1. 25.4.4.1.1 Range Filter
          2. 25.4.4.1.2 Filter for specific IDs
          3. 25.4.4.1.3 Classic Bit Mask Filter
          4. 25.4.4.1.4 Standard Message ID Filtering
          5. 25.4.4.1.5 Extended Message ID Filtering
        2. 25.4.4.2 Rx FIFOs
          1. 25.4.4.2.1 Rx FIFO Blocking Mode
          2. 25.4.4.2.2 Rx FIFO Overwrite Mode
        3. 25.4.4.3 Dedicated Rx Buffers
          1. 25.4.4.3.1 Rx Buffer Handling
        4. 25.4.4.4 Debug on CAN Support
          1. 25.4.4.4.1 Filtering for Debug Messages
          2. 25.4.4.4.2 Debug Message Handling
      5. 25.4.5 Tx Handling
        1. 25.4.5.1 Transmit Pause
        2. 25.4.5.2 Dedicated Tx Buffers
        3. 25.4.5.3 Tx FIFO
        4. 25.4.5.4 Tx Queue
        5. 25.4.5.5 Mixed Dedicated Tx Buffers / Tx FIFO
        6. 25.4.5.6 Mixed Dedicated Tx Buffers / Tx Queue
        7. 25.4.5.7 Transmit Cancellation
        8. 25.4.5.8 Tx Event Handling
      6. 25.4.6 FIFO Acknowledge Handling
      7. 25.4.7 DCAN Message RAM
        1. 25.4.7.1 Message RAM Configuration
        2. 25.4.7.2 Rx Buffer and FIFO Element
        3. 25.4.7.3 Tx Buffer Element
        4. 25.4.7.4 Tx Event FIFO Element
        5. 25.4.7.5 Standard Message ID Filter Element
        6. 25.4.7.6 Extended Message ID Filter Element
      8. 25.4.8 Interrupt Requests
    5. 25.5 DCAN Wrapper
    6. 25.6 DCAN Clock Enable
    7. 25.7 DCAN Registers
  27. 26Revision History

5.2.2 Fault Escalation to HardFault

All fault exceptions other than HardFault have configurable exception priority. Software can disable execution of the handlers for these faults.

Usually, the exception priority, together with the values of the exception mask registers, determines whether the processor enters the fault handler, and whether a fault handler can preempt another fault handler.

In some situations, a fault with configurable priority is treated as a HardFault. This is called priority escalation, and the fault is described as escalated to HardFault. Escalation to HardFault occurs when:

  • A fault handler causes the same kind of fault as the one it is servicing. This escalation to HardFault occurs because a fault handler cannot preempt itself; it must have the same priority as the current execution priority level.
  • A fault handler causes a fault with the same or lower priority as the fault it is servicing. This is because the handler for the new fault cannot preempt the currently executing fault handler.
  • An exception handler causes a fault for which the priority is the same as or lower than the currently executing exception.
  • A fault occurs and the handler for that fault is not enabled. If a BusFault occurs during a stack push when entering a BusFault handler, the BusFault does not escalate to a HardFault. This means that if a corrupted stack causes a fault, the fault handler executes even though the stack push for the handler failed. The fault handler operates but the stack contents are corrupted.

If a BusFault occurs during a stack push when entering a BusFault handler, the BusFault does not escalate to a HardFault. This means that if a corrupted stack causes a fault, the fault handler executes even though the stack push for the handler failed. The fault handler operates but the stack contents are corrupted.

BusFaults and fixed priority exceptions can be designated as Secure or Non-secure under the control of SCB.AIRCR[13] BFHFNMINS. When SCB.AIRCR[13] BFHFMNINS is set to:

  • 0: BusFaults and fixed priority exceptions are designated as Secure. The exceptions retain the prioritization of HardFault at -1 and NMI at -2.
  • 1: BusFaults and fixed priority exceptions are designated as Non-secure. In this case, Secure HardFault is introduced at priority -3 to ensure that faults that target Secure state are recognized.

The Non-secure state cannot inhibit BusFaults and fixed priority exceptions which target Secure state. Therefore when faults and fixed priority exceptions are Secure, Non-secure FAULTMASK (FAULTMASK_NS) only inhibits programmable priority exceptions, making it equivalent to Non-secure PRIMASK (PRIMASK_NS).

Non-secure programmable priority exceptions are mapped to the regular priority range 0-255, if SCB.AIRCR[14] PRIS is clear. Non-secure programmable priority exceptions are mapped to the bottom half the regular priority range, 128-255, if AIRCR.PRIS is set to 1. Therefore, the FAULTMASK_NS sets the execution priority to 0x0 or 0x80, according to AIRCR.PRIS, to mask the Non-secure programmable priority exception only.

When BusFaults and fixed priority exceptions are Secure, FAULTMASK_S sets execution priority to -1 to inhibit everything up to and including HardFault.

When BusFaults and fixed priority exceptions are designated as Non-secure, FAULTMASK_NS boosts priority to -1 to inhibit everything up to Non-secure HardFault at priority -1, while FAULTMASK_S boosts priority to -3 to inhibit all faults and fixed priority exceptions including the Secure HardFault at priority -3.

Note: Only Reset can preempt the fixed priority Secure HardFault when SCB.AIRCR[13] BFHFNMINS is set to 1. A Secure HardFault when SCB.AIRCR[13] BFHFNMINS is set to 1 can preempt any exception other than Reset.

A Secure HardFault when SCB.AIRCR[13] BFHFNMINS is set to 0 can preempt any exception other than Reset, NMI, or another HardFault.