SPRUIY2 November   2024 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)
      2. 3.2.2 NMI (Non-Maskable Interrupt)
      3. 3.2.3 RTINT (Real Time Interrupt)
      4. 3.2.4 INT (Low-Priority Interrupt)
    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. 4Pipeline
    1. 4.1  Introduction
    2. 4.2  Decoupled Pipeline Phases
    3. 4.3  Dual Instruction Prefetch Buffers
    4. 4.4  Pipeline Advancement and Stalls
    5. 4.5  Pipeline Hazards and Protection Mechanisms
    6. 4.6  Register Updates and Corresponding Pipeline Phases
    7. 4.7  Register Reads and Writes During Normal Operation
    8. 4.8  D2 Read Protection
    9. 4.9  E1 Read Protection
    10. 4.10 WAW Protection
    11. 4.11 Protection During Interrupt
  7. 5Addressing Modes
    1. 5.1 Addressing Modes Overview
      1. 5.1.1 Documentation and Implementation
      2. 5.1.2 List of Addressing Mode Types
        1. 5.1.2.1 Additional Types of Addressing
      3. 5.1.3 Addressing Modes Summarized
    2. 5.2 Addressing Mode Fields
      1. 5.2.1 ADDR1 Field
      2. 5.2.2 ADDR2 Field
      3. 5.2.3 ADDR3 Field
      4. 5.2.4 DIRM Field
      5. 5.2.5 Additional Fields
    3. 5.3 Alignment and Pipeline Considerations
      1. 5.3.1 Alignment
      2. 5.3.2 Pipeline Considerations
    4. 5.4 Types of Addressing Modes
      1. 5.4.1 Direct Addressing
      2. 5.4.2 Pointer Addressing
        1. 5.4.2.1 Pointer Addressing with #Immediate Offset
        2. 5.4.2.2 Pointer Addressing with Pointer Offset
        3. 5.4.2.3 Pointer Addressing with #Immediate Increment/Decrement
        4. 5.4.2.4 Pointer Addressing with Pointer Increment/Decrement
      3. 5.4.3 Stack Addressing
        1. 5.4.3.1 Allocating and De-allocating Stack Space
      4. 5.4.4 Circular Addressing Instruction
      5. 5.4.5 Bit Reversed Addressing Instruction
  8. 6Safety and Security Unit (SSU)
    1. 6.1 SSU Overview
    2. 6.2 Links and Task Isolation
    3. 6.3 Sharing Data Outside Task Isolation Boundary
    4. 6.4 Protected Call and Return
  9. 7Emulation
    1. 7.1 Overview of Emulation Features
    2. 7.2 Debug Terminology
    3. 7.3 Debug Interface
    4. 7.4 Execution Control Mode
    5. 7.5 Breakpoints, Watchpoints, and Counters
      1. 7.5.1 Software Breakpoint
      2. 7.5.2 Hardware Debugging Resources
        1. 7.5.2.1 Hardware Breakpoint
        2. 7.5.2.2 Hardware Watchpoint
        3. 7.5.2.3 Benchmark Counters
      3. 7.5.3 PC Trace
  10. 8Revision History

3.6.2 LINK

A LINK is a unique collection of ownerships and access permissions tagged together by ID which is used for resource allocation and sharing. Link ID binds CPU resources like stack, memory regions, peripheral instance accesses, interrupt source and vectors, DMA channels and permissions, and more. This prevents resources from being accessed from a hacker (or erroneous code) running from another Link. Of particular interest to this chapter is the access provided by a LINK to particular interrupt sources and vectors.

The following provides the types of links utilized for interrupt operation.

  1. Owner link: every interrupt line and associated interrupt vector has an owner link.
    • This link has related resources of the source events like peripheral, GPIO or error mechanism.
    • Owner link has access to memory, DMA or other resources needed to service the specific event.
    • Owner link has access to control and status register to read flag, enable/disable an interrupt line, clear the flag or force the flag high. As well has permissions to read and clear the overflow flag.
    • The Current Link ID provided by the CPU is compared against owner link for Interrupt operational registers.
  2. Boot link: boot link handles device boot and initialization including that of interrupts.
    • User Boot Link: User boot links do not have special privileges to access PIPE or interrupt registers.
  3. Secure root Link: This is the root of trust for security code of the device and shall have access to PIPE configuration registers and vector table. Configuration registers hold information like the owner link, caller link, priority, vector address of the interrupt line.
  4. Caller Link: Caller links are used to share common code libraries across multiple links.
    • The owner link of an interrupt line (like RTINTn) can call a common code function (from another link) in an ISR. In such a case, it is checked whether the caller link is the owner link.
    • Configuration registers like priority can only be updated by the “secure root link”. In this case, the owner link can be the caller link of a “Secure Root Link” function.