- •Chapter 1. Introduction
- •How to Develop A Program
- •What is an Assembler?
- •Modular Programming
- •Modular Program Development Process
- •Segments, Modules, and Programs
- •Translate and Link Process
- •Filename Extensions
- •Program Template File
- •Chapter 2. Architecture Overview
- •Memory Classes and Memory Layout
- •Classic 8051
- •Extended 8051 Variants
- •Philips 80C51MX
- •Intel/Atmel WM 251
- •CPU Registers
- •CPU Registers of the 8051 Variants
- •CPU Registers of the Intel/Atmel WM 251
- •Program Status Word (PSW)
- •Instruction Sets
- •Opcode Map
- •8051 Instructions
- •Additional 251 Instructions
- •Additional 80C51MX Instructions via Prefix A5
- •Chapter 3. Writing Assembly Programs
- •Assembly Statements
- •Directives
- •Controls
- •Instructions
- •Comments
- •Symbols
- •Symbol Names
- •Labels
- •Operands
- •Special Assembler Symbols
- •Immediate Data
- •Memory Access
- •Program Addresses
- •Expressions and Operators
- •Numbers
- •Characters
- •Character Strings
- •Location Counter
- •Operators
- •Expressions
- •Chapter 4. Assembler Directives
- •Introduction
- •Segment Directives
- •Location Counter
- •Generic Segments
- •Stack Segment
- •Absolute Segments
- •Default Segment
- •SEGMENT
- •RSEG
- •BSEG, CSEG, DSEG, ISEG, XSEG
- •Symbol Definition
- •CODE, DATA, IDATA, XDATA
- •esfr, sfr, sfr16, sbit
- •LIT (AX51 & A251 only)
- •Memory Initialization
- •DD (AX51 & A251 only)
- •Reserving Memory
- •DBIT
- •DSW (AX51 & A251 only)
- •DSD (AX51 & A251 only)
- •Procedure Declaration (AX51 & A251 only)
- •PROC / ENDP (AX51 & A251 only)
- •LABEL (AX51 and A251 only)
- •Program Linkage
- •PUBLIC
- •EXTRN / EXTERN
- •NAME
- •Address Control
- •EVEN (AX51 and A251 only)
- •USING
- •Other Directives
- •_ _ERROR_ _
- •Chapter 5. Assembler Macros
- •Standard Macro Directives
- •Defining a Macro
- •Parameters
- •Labels
- •Repeating Blocks
- •REPT
- •IRPC
- •Nested Definitions
- •Nested Repeating Blocks
- •Recursive Macros
- •Operators
- •NUL Operator
- •& Operator
- •< and > Operators
- •% Operator
- •;; Operator
- •! Operator
- •Invoking a Macro
- •C Macros
- •C Macro Preprocessor Directives
- •Stringize Operator
- •Predefined C Macro Constants
- •Examples with C Macros
- •C Preprocessor Side Effects
- •Chapter 6. Macro Processing Language
- •Overview
- •Creating and Calling MPL Macros
- •Creating Parameterless Macros
- •MPL Macros with Parameters
- •Local Symbols List
- •Macro Processor Language Functions
- •Comment Function
- •Escape Function
- •Bracket Function
- •METACHAR Function
- •Numbers and Expressions
- •Numbers
- •Character Strings
- •SET Function
- •EVAL Function
- •Logical Expressions and String Comparison
- •Conditional MPL Processing
- •IF Function
- •WHILE Function
- •REPEAT Function
- •EXIT Function
- •String Manipulation Functions
- •LEN Function
- •SUBSTR Function
- •MATCH Function
- •Console I/O Functions
- •Advanced Macro Processing
- •Literal Delimiters
- •Blank Delimiters
- •Identifier Delimiters
- •Literal and Normal Mode
- •MACRO Errors
- •Chapter 7. Invocation and Controls
- •Environment Settings
- •Running Ax51
- •ERRORLEVEL
- •Output Files
- •Assembler Controls
- •Controls for Conditional Assembly
- •Conditional Assembly Controls
- •Chapter 8. Error Messages
- •Fatal Errors
- •Non–Fatal Errors
- •Chapter 9. Linker/Locator
- •Overview
- •Combining Program Modules
- •Segment Naming Conventions
- •Combining Segments
- •Locating Segments
- •Overlaying Data Memory
- •Resolving External References
- •Absolute Address Calculation
- •Generating an Absolute Object File
- •Generating a Listing File
- •Bank Switching
- •Using RTX51, RTX251, and RTX51 Tiny
- •Linking Programs
- •Command Line Examples
- •Control Linker Input with µVision2
- •ERRORLEVEL
- •Output File
- •Linker/Locater Controls
- •Locating Programs to Physical Memory
- •Classic 8051
- •Extended 8051 Variants
- •Philips 80C51MX
- •Intel/Atmel WM 251
- •Data Overlaying
- •Program and Data Segments of Functions
- •Using the Overlay Control
- •Tips and Tricks for Program Locating
- •Locate Segments with Wildcards
- •Special ROM Handling (LX51 & L251 only)
- •Bank Switching
- •Common Code Area
- •Code Bank Areas
- •Bank Switching Configuration
- •Configuration Examples
- •Control Summary
- •Listing File Controls
- •Output File Controls
- •Segment and Memory Location Controls
- •High-Level Language Controls
- •Error Messages
- •Warnings
- •Non-Fatal Errors
- •Fatal Errors
- •Exceptions
- •Chapter 10. Library Manager
- •Using LIBx51
- •Interactive Mode
- •Create Library within µVision2
- •Command Summary
- •Creating a Library
- •Adding or Replacing Object Modules
- •Removing Object Modules
- •Extracting Object Modules
- •Listing Library Contents
- •Error Messages
- •Fatal Errors
- •Errors
- •Chapter 11. Object-Hex Converter
- •Using OHx51
- •OHx51 Command Line Examples
- •Creating HEX Files for Banked Applications
- •OHx51 Error Messages
- •Using OC51
- •OC51 Error Messages
- •Intel HEX File Format
- •Record Format
- •Data Record
- •Extended 8086 Segment Record
- •Extended Linear Address Record
- •Example Intel HEX File
- •Appendix A. Application Examples
- •ASM – Assembler Example
- •Using A51 and BL51
- •Using AX51 and LX51
- •Using A251 and L251
- •CSAMPLE – C Compiler Example
- •Using C51 and BL51
- •Using C51 and LX51
- •Using C251 and L251
- •BANK_EX1 – Code Banking with C51
- •Using C51 and BL51
- •Using C51 and LX51
- •BANK_EX2 – Banking with Constants
- •Using C51 and BL51
- •Using C51 and LX51
- •Using BL51
- •Using C51 and LX51
- •Philips 80C51MX – Assembler Example
- •Philips 80C51MX – C Compiler Example
- •Appendix B. Reserved Symbols
- •Appendix C. Listing File Format
- •Assembler Listing File Format
- •Listing File Heading
- •Source Listing
- •Macro / Include File / Save Stack Format
- •Symbol Table
- •Listing File Trailer
- •Appendix D. Assembler Differences
- •Differences Between A51 and A251/AX51
- •Differences between A51 and ASM51
- •Differences between A251/AX51 & ASM51
- •Glossary
- •Index
404 Appendix A. Application Examples
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BANK_EX1 – Code Banking with C51 |
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A |
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The following C51 example shows how to compile and link a program using |
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multiple code banks. |
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The program begins with function main in C_ROOT.C. The main function calls |
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functions in other code banks. These functions, in turn, call functions in yet |
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different code banks. The printf function outputs the number of the code bank |
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in each function. |
Keil Software — A51/AX51/A251 Macro Assembler and Utilities |
405 |
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Using C51 and BL51
The program can be translated using the following commands:
C51 C_ROOT.C DEBUG OBJECTEXTEND
C51 C_BANK0.C DEBUG OBJECTEXTEND
C51 C_BANK1.C DEBUG OBJECTEXTEND
C51 C_BANK2.C DEBUG OBJECTEXTEND
A
contains the main function and is located in the common area. C_BANK0.C, C_BANK1.C, and C_BANK2.C contain the bank functions and are located in the bank area. The BL51 linker/locator is invoked as follows:
BL51 COMMON{C_ROOT.OBJ}, BANK0{C_BANK0.OBJ},
BANK1{C_BANK1.OBJ}, BANK2{C_BANK2.OBJ}
BANKAREA(8000H,0FFFFH)
The BANKAREA (8000H, 0FFFFH) control defines the address space 80000H to 0FFFFH as the area for code banks. The COMMON control places the C_ROOT.OBJ module in the common area. The BANK0, BANK1, and BANK2 controls place modules in bank 0, 1, and 2 respectively.
The BL51 linker/locator creates a listing file, C_ROOT.M51, which contains information about memory allocation and about the intra-bank jump table that is generated. BL51 also creates the output file C_ROOT that in banked object file format. You must use the OC51 banked object file converter to convert this file into standard object files:
OC51 C_ROOT
For this example program, the OC51 banked object file converter produces three standard object files from C_ROOT. They are listed in the following table.
Filename Contents
C_ROOT.B00 All information (including symbols) for code bank 0 and the common area.
C_ROOT.B01 Information for code bank 1 and the common area.
C_ROOT.B02 Information for code bank 2 and the common area.
You can create Intel HEX files for each of these object files by using the OH51 object to hex converter. The Intel HEX files you create with OH51 contain complete information for each code bank including the common area:
OH51 C_ROOT.B00 HEXFILE (C_ROOT.H00)
OH51 C_ROOT.B01 HEXFILE (C_ROOT.H01)
OH51 C_ROOT.B02 HEXFILE (C_ROOT.H02)
406 Appendix A. Application Examples
Using C51 and LX51
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When you are using the extended LX51 linker/locater the program is generated |
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as shown below: |
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C51 |
C_ROOT.C |
DEBUG OMF251 |
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C51 |
C_BANK0.C |
DEBUG OMF251 |
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C51 |
C_BANK1.C |
DEBUG OMF251 |
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C51 |
C_BANK2.C |
DEBUG OMF251 |
LX51 COMMON{C_ROOT.OBJ}, BANK0{C_BANK0.OBJ},
BANK1{C_BANK1.OBJ}, BANK2{C_BANK2.OBJ}
BANKAREA(8000H,0FFFFH)
The LX51 linker/locator creates a listing file, C_ROOT.MAP, which contains information about memory allocation and about the intra-bank jump table that is generated. The linker output file C_ROOT can be directly converted into an Intel HEX file with OHX51:
OHX51 C_ROOT