TMS320C28x Assembly Language Tools v18.1.0.LTS User's Guide Literature Number: SPRU513P January 2018 Contents Preface....................................................................................................................................... 11 1 Introduction to the Software Development Tools.................................................................... 14 1.1 Software Development Tools Overview ................................................................................. 15 1.2 Tools Descriptions.......................................................................................................... 16 2 Introduction to Object Modules ............................................................................................ 17 2.1 Executable Object Files ................................................................................................... 18 2.2 Introduction to Sections ................................................................................................... 18 2.2.1 Special Section Names........................................................................................... 19 2.3 How the Assembler Handles Sections .................................................................................. 20 2.3.1 Uninitialized Sections ............................................................................................. 20 2.3.2 Initialized Sections ................................................................................................ 21 2.3.3 User-Named Sections ............................................................................................ 21 2.3.4 Current Section .................................................................................................... 22 2.3.5 Section Program Counters ....................................................................................... 22 2.3.6 Subsections ........................................................................................................ 22 2.3.7 Using Sections Directives ........................................................................................ 23 2.4 How the Linker Handles Sections........................................................................................ 26 2.4.1 Combining Input Sections ........................................................................................ 26 2.4.2 Placing Sections................................................................................................... 27 2.5 Symbols ..................................................................................................................... 28 2.5.1 External Symbols.................................................................................................. 28 2.5.2 The Symbol Table................................................................................................. 29 2.6 Symbolic Relocations ...................................................................................................... 29 2.6.1 Expressions With Multiple Relocatable Symbols (COFF Only) ............................................. 29 2.7 Loading a Program......................................................................................................... 30 3 Program Loading and Running ............................................................................................ 31 3.1 Loading ...................................................................................................................... 32 3.1.1 Load and Run Addresses ........................................................................................ 32 3.1.2 Bootstrap Loading................................................................................................. 33 3.2 Entry Point................................................................................................................... 37 3.3 Run-Time Initialization ..................................................................................................... 37 3.3.1 _c_int00............................................................................................................. 37 3.3.2 RAM Model vs. ROM Model ..................................................................................... 38 3.3.3 Copy Tables........................................................................................................ 39 3.4 Arguments to main ......................................................................................................... 40 3.5 Run-Time Relocation ...................................................................................................... 40 3.6 Additional Information...................................................................................................... 40 4 Assembler Description........................................................................................................ 41 4.1 Assembler Overview ....................................................................................................... 42 4.2 The Assembler's Role in the Software Development Flow ........................................................... 43 4.3 Invoking the Assembler.................................................................................................... 44 4.4 Naming Alternate Directories for Assembler Input..................................................................... 45 4.4.1 Using the --include_path Assembler Option ................................................................... 45 4.4.2 Using the C2000_A_DIR Environment Variable .............................................................. 46 2 Contents SPRU513P–January 2018 Submit Documentation Feedback Copyright © 2018, Texas Instruments Incorporated www.ti.com 4.5 Source Statement Format................................................................................................. 47 4.5.1 Label Field.......................................................................................................... 48 4.5.2 Mnemonic Field.................................................................................................... 49 4.5.3 Operand Field...................................................................................................... 49 4.5.4 Comment Field .................................................................................................... 49 4.6 Literal Constants ........................................................................................................... 50 4.6.1 Integer Literals ..................................................................................................... 50 4.6.2 Character String Literals.......................................................................................... 51 4.6.3 Floating-Point Literals............................................................................................. 52 4.7 Assembler Symbols ........................................................................................................ 52 4.7.1 Identifiers ........................................................................................................... 52 4.7.2 Labels............................................................................................................... 53 4.7.3 Local Labels........................................................................................................ 53 4.7.4 Symbolic Constants ............................................................................................... 56 4.7.5 Defining Symbolic Constants (--asm_define Option) ......................................................... 56 4.7.6 Predefined Symbolic Constants ................................................................................. 57 4.7.7 Registers ........................................................................................................... 58 4.7.8 Substitution Symbols.............................................................................................. 59 4.8 Expressions ................................................................................................................. 60 4.8.1 Mathematical and Logical Operators ........................................................................... 61 4.8.2 Relational Operators and Conditional Expressions........................................................... 62 4.8.3 Well-Defined Expressions........................................................................................ 62 4.8.4 Legal Expressions................................................................................................. 62 4.9 Built-in Functions and Operators ......................................................................................... 63 4.9.1 Built-In Math and Trigonometric Functions .................................................................... 63 4.10 TMS320C28x Assembler Modes......................................................................................... 64 4.10.1 C28x Object Mode ............................................................................................... 64 4.10.2 C28x FPU32 Object Mode ...................................................................................... 64 4.10.3 C28x CLA Object Mode ......................................................................................... 64 4.11 Source Listings ............................................................................................................. 66 4.12 Debugging Assembly Source ............................................................................................