SPRUIY2A November   2024  – March 2025 F29H850TU , F29H859TU-Q1

 

  1.   1
  2.   Read This First
    1.     About This Manual
    2.     Related Documentation from Texas Instruments
    3.     Glossary
    4.     Support Resources
    5.     Trademarks
  3. 1Architecture Overview
    1. 1.1 Introduction to the CPU
    2. 1.2 Data Type
    3. 1.3 C29x CPU System Architecture
      1. 1.3.1 Emulation Logic
      2. 1.3.2 CPU Interface Buses
    4. 1.4 Memory Map
  4. 2Central Processing Unit (CPU)
    1. 2.1 C29x CPU Architecture
      1. 2.1.1 Features
      2. 2.1.2 Block Diagram
    2. 2.2 CPU Registers
      1. 2.2.1 Addressing Registers (Ax/XAx)
      2. 2.2.2 Fixed-Point Registers (Dx/XDx)
      3. 2.2.3 Floating-Point Register (Mx/XMx)
      4. 2.2.4 Program Counter (PC)
      5. 2.2.5 Return Program Counter (RPC)
      6. 2.2.6 Status Registers
        1. 2.2.6.1 Interrupt Status Register (ISTS)
        2. 2.2.6.2 Decode Phase Status Register (DSTS)
        3. 2.2.6.3 Execute Phase Status Register (ESTS)
    3. 2.3 Instruction Packing
      1. 2.3.1 Standalone Instructions and Restrictions
      2. 2.3.2 Instruction Timeout
    4. 2.4 Stacks
      1. 2.4.1 Software Stack
      2. 2.4.2 Protected Call Stack
      3. 2.4.3 Real Time Interrupt / NMI Stack
  5. 3Interrupts
    1. 3.1 CPU Interrupts Architecture Block Diagram
    2. 3.2 RESET, NMI, RTINT, and INT
      1. 3.2.1 RESET (CPU reset)
        1. 3.2.1.1 Required Instructions (RESET)
      2. 3.2.2 NMI (Non-Maskable Interrupt)
        1. 3.2.2.1 Blocking and Masking (NMI)
        2. 3.2.2.2 Signal Propagation (NMI)
        3. 3.2.2.3 Stack (NMI)
        4. 3.2.2.4 Required Instructions (NMI)
      3. 3.2.3 RTINT (Real-Time Interrupt)
        1. 3.2.3.1 Blocking and Masking (RTINT)
        2. 3.2.3.2 Signal Propagation (RTINT)
        3. 3.2.3.3 Stack (RTINT)
        4. 3.2.3.4 Required Instructions (RTINT)
      4. 3.2.4 INT (Low-Priority Interrupt)
        1. 3.2.4.1 Blocking and Masking (INT)
        2. 3.2.4.2 Signal Propagation (INT)
        3. 3.2.4.3 Stack (INT)
    3. 3.3 Conditions Blocking Interrupts
      1. 3.3.1 ATOMIC Counter
    4. 3.4 CPU Interrupt Control Registers
      1. 3.4.1 Interrupt Status Register (ISTS)
      2. 3.4.2 Decode Phase Status Register (DSTS)
      3. 3.4.3 Interrupt-Related Stack Registers
    5. 3.5 Interrupt Nesting
      1. 3.5.1 Interrupt Nesting Example Diagram
    6. 3.6 Security
      1. 3.6.1 Overview
      2. 3.6.2 LINK
      3. 3.6.3 STACK
      4. 3.6.4 ZONE
  6. 4Addressing Modes
    1. 4.1 Addressing Modes Overview
      1. 4.1.1 Documentation and Implementation
      2. 4.1.2 List of Addressing Mode Types
        1. 4.1.2.1 Additional Types of Addressing
      3. 4.1.3 Addressing Modes Summarized
    2. 4.2 Addressing Mode Fields
      1. 4.2.1 ADDR1 Field
      2. 4.2.2 ADDR2 Field
      3. 4.2.3 ADDR3 Field
      4. 4.2.4 DIRM Field
      5. 4.2.5 Additional Fields
    3. 4.3 Alignment and Pipeline Considerations
      1. 4.3.1 Alignment
      2. 4.3.2 Pipeline Considerations
    4. 4.4 Types of Addressing Modes
      1. 4.4.1 Direct Addressing
      2. 4.4.2 Pointer Addressing
        1. 4.4.2.1 Pointer Addressing with #Immediate Offset
        2. 4.4.2.2 Pointer Addressing with Pointer Offset
        3. 4.4.2.3 Pointer Addressing with #Immediate Increment/Decrement
        4. 4.4.2.4 Pointer Addressing with Pointer Increment/Decrement
      3. 4.4.3 Stack Addressing
        1. 4.4.3.1 Allocating and De-allocating Stack Space
      4. 4.4.4 Circular Addressing Instruction
      5. 4.4.5 Bit Reversed Addressing Instruction
  7. 5Safety and Security Unit (SSU)
    1. 5.1 SSU Overview
    2. 5.2 Links and Task Isolation
    3. 5.3 Sharing Data Outside Task Isolation Boundary
    4. 5.4 Protected Call and Return
  8. 6Emulation
    1. 6.1 Overview of Emulation Features
    2. 6.2 Debug Terminology
    3. 6.3 Debug Interface
    4. 6.4 Execution Control Mode
    5. 6.5 Breakpoints, Watchpoints, and Counters
      1. 6.5.1 Software Breakpoint
      2. 6.5.2 Hardware Debugging Resources
        1. 6.5.2.1 Hardware Breakpoint
        2. 6.5.2.2 Hardware Watchpoint
        3. 6.5.2.3 Benchmark Counters
      3. 6.5.3 PC Trace
  9. 7Revision History

3.2.2.4 Required Instructions (NMI)

NMI and RTINT interrupts can potentially have the respective interrupt service routines (ISRs) residing in a different LINK/STACK. Therefore, NMI and RTINT ISRs require that the first instruction packet of every vector address contain the (ISR1.PROT || ISR2.PROT) instructions. The CPU pipeline control hardware checks for these required instructions and generates a FAULT, if these instructions are not the first instruction packet of the ISR. These required instructions are inserted automatically by the compiler, but must be configured to do so for the appropriate vectors within a separate security settings file. See Section 3.6 for more details.

ISR1.PROT also initializes the stack pointer (A15) to the appropriate STACK by performing the following operation: A15 = SECSPn (where n is the current STACK indicated by ISTS.CURRSP).

For more details on the security implications of the LINK/STACK/ZONE and memory space for CPU interrupts, see Section 3.6.