STMicrolectronics ST7 Assembler Linker User manual

STMicrolectronics
ST7 Assembler
Linker
UM0144
User manual
Rev 2
June 2005

BLANK

Rev 2
June 2005 UM0144 3/92
4
UM0144
User Manual
ST7 Assembler Linker
Introduction
Thanks for choosing ST7! This manual describes how to use the ST7 Assembler-Linker to
develop applications for ST7 microcontrollers. The assembly tools described in this book form a
development system that assembles, links and formats your source code.
The ST7 Assembler-Linker includes the following tools:
●Assembler (ASM): translates your source code (.ASM) written in assembly language, into
object code (.OBJ) specific to the target machine and an optional listing file (.LST).
●Linker (LYN): processes the object files (.OBJ) produced by the assembler, resolves all
cross-references between object files and locates all the modules in memory. The
resulting code is output in an object code file (.COD). In a second pass, the Assembler
uses these files to produce an object code file, map and listing with absolute paths.
●Obsend (OBS): translates the object code file to produce the final executable in a default
format (.FIN) or other format that you specify (e.g. ST S-record, Motorola S-record, Intel
Hex...).
●LIB (Librarian): The librarian enables you to store frequently used subroutines in one
location for use with any number of ST7 applications.
Figure 1. Schematic overview of the ST7 assembler toolset
www.st.com

ST7 Assembler Linker
4/92 UM0144
Note: The utility file asli.bat automatically runs ASM, LYN, and OBSEND one after the other for you. Use this batch file only
if you have only one assembly source file ".ASM".
About the user manuals...
This manual provides information about producing an application executable for ST7 from your
application source code in Assembly language. Here, you will find:
●An overview of Assembly language for ST7
●Instructions for running the ST7 Assembler-Linker
●Descriptions of the Assembler output
For information on related subjects refer to the following documentation:
ST7xxxx Datasheet – full description of your ST7.
ST7 Programming Manual – a complete reference to ST7 Assembly language
Host PC system requirements
This tool has been designed to operate on a PC that meets the following:
●One of the following operating systems: Microsoft®Windows®98, 2000, Millennium, NT®
or XP®.
●Intel®Pentium (or compatible) processor with minimum speed of 133 MHz.
●Minimum RAM of 32 MB (64 MB recommended).
●60 MB of free hard disk space to install all of the ST7 tools.
Getting assistance
For more information, application notes, FAQs and software updates for all the ST
microcontroller development tools, check out the CD-ROM or our website:
www.st.com/mcu
For assistance on all ST microcontroller subjects, or for help developing applications that use
your microcontroller’s MSCI peripheral, refer to the contact list provided in
Product Support on
page 108. We’ll be glad to help you.

ST7 Assembler Linker
UM0144 5/92
Contents
1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 ST7 Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Overview of ST7 addressing modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 General instruction syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Short and long addressing modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4 Inherent addressing mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.5 Immediate operands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.6 Direct and indirect modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.7 Indexed modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.8 Relative mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.9 High, low addressing modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3 ST7 Assembler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2 Source files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.3 Assembly source code format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4 Segmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.5 Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.6 Conditional assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.7 Running the assembler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4 Linker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.1 What the linker does . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.2 Invoking the linker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.3 Command line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.4 Linking in detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.5 The linker in more detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5 OBSEND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.1 What OBSEND does for you . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.2 Invoking OBSEND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

ST7 Assembler Linker
6/92 UM0144
6 Librarian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.2 Invoking the librarian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.3 Adding modules to a library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.4 Deleting modules from a library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.5 Copying modules from a library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.6 Getting details in your library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Appendix A Assembler Directives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Appendix B Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Appendix C Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Appendix D Product Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

ST7 Assembler Linker 1 Getting Started
UM0144 7/92
1 Getting Started
Installing the ST7 Assembler-Linker
The ST7 Assembler-Linker is delivered as part of the ST7 toolset. A free installation package is available
at www.st.com/mcu. To install it:
1. Select ST7>ST7 toolchain from the main menu of the “Microcontroller Development
Tools” CD-ROM, or...
2. Run the installation executable that you have downloaded from the internet.
Note: Windows
®
2000, NT®and XP®users must have administrator privileges to install certain
software components.
After installation, the installation directory should contain the following ( Table 1 ):.
Up-to-date release notes are provided in PDF format. An additional file contains demonstration examples.
Table 1. Description of installed files
ASM.EXE ST7 Assembler
LYN.EXE ST7 Linker
OBSEND.EXE output file formatter
LIB.EXE librarian
ST7.TAB ST7 description files
ASLI.BAT batch file ASM+LYN+OBSEND
RELEASE_NOTES.PDF release notes

2 ST7 Addressing Modes ST7 Assembler Linker
8/92 UM0144
2 ST7 Addressing Modes
2.1 Overview of ST7 addressing modes
The ST7 assembler instruction set incorporates the following different addressing modes:
All ST7 addressing modes are described in full detail, with specific examples, in the
ST7 Family
8-bit MCUs Programming Manual
. This chapter seeks only to give a brief explanation of the
main addressing mode types.
2.2 General instruction syntax
The ST7 instruction set provide a single source-coding model regardless of which components
are operands—the accumulator (A), an index register (X or Y), an 8-bit stack pointer (S) for
ST7, the condition code register (CC), or a memory location. For example, a single instruction,
ld, originates register to register transfers as well as memory to accumulator data movements.
Table 2. ST7 Addressing modes
Instruction Set Addressing Mode Example
ST7
Inherent nop
Immediate ld A,#$F5
Direct (short address) ld A,$F5
Direct (long address) ld A,$F5C2
X or Y Indexed (no offset) ld A,(X)
X or Y Indexed (short offset) ld A,($F5,X)
X or Y Indexed (long offset) ld A,($F5C2,X)
Short Pointer Indirect (short pointed data) ld A,[$F5]
Short Pointer Indirect (long pointed data) ld A,[$F5.w]
Short Pointer Indirect (short pointed data) X
or Y Indexed ld A,([$F5],X)
Short Pointer Indirect (long pointed data) X or
Y Indexed ld A,([$F5.w],X)
Direct Relative (short offset) jrt $F5
Short Pointer Indirect Relative (short pointed
data) jrt [$F5]
Bit operation bset byte, #5

ST7 Assembler Linker 2 ST7 Addressing Modes
UM0144 9/92
Two-operand instructions are coded with destination operand appearing at first position. For
example:
2.3 Short and long addressing modes
For ST7 there are two addressing modes that differ in memory address size (i.e. one byte for
short mode and two bytes for long mode).
Because of these different addressing modes, the target address range of the operands will
depend upon the addressing mode chosen:
Some instructions accept both long and short addressing modes, while others only accept one
or the other.
For example:
For ST7 instructions supporting both short and long formats, when external symbols are
referenced, long mode is chosen by the Assembler. For example:
2.4 Inherent addressing mode
This concept is hardware-oriented, meaning that instruction operands are coded inside the
operation code. At the source coding level, operands are written explicitly.
Examples:
lab01 ld A,memory ; load accumulator A with memory contents
lab02 ld memory,A ; load memory location with A contents
ld X,A ; load X with accumulator contents
0-$FF for short addressing mode
$100-$FFFF for long addressing mode
lab10 add A,memory ; accepts both types of addressing modes
lab11 inc memory ; accepts only short addressing mode
EXTERN symb3 ;
symb1 equ $10 ;
...
ld A,symb1 ; short mode
ld A,symb3 ; long mode chosen
lab06 push A ; put accumulator A onto the stack
lab07 mul X,A ; multiply X by A

2 ST7 Addressing Modes ST7 Assembler Linker
10/92 UM0144
2.5 Immediate operands
Immediate operands permit you to input a specific value for use with an instruction. They are
signaled by the use of a sharp sign (#) before the value.
Examples:
The range for an 8-bit immediate operand is from 0 to 255.
2.6 Direct and indirect modes
A direct addressing mode means that the data byte required to do the operation is found by
its memory address, which follows the op-code.
An indirect addressing mode means that the data byte required to do the operation is found
by its memory address which is located in memory (pointer). The pointer address follows the
op-code.
This last group consists of memory indirect variants:
●short indirect (short pointed data),
●long indirect (long pointed data),
●short indirect indexed (short pointed data),
●long indirect indexed (long pointed data),
For ST7 devices, the address specified must always be in page 0 (i.e. its address must be less
than $100). Examples:
To make the distinction between short and long indirect addressing mode, the suffix.w is
specified to indicate that you want to work in long indirect mode (this is also true for indexed
addressing mode). Implicitly, if nothing is specified, the short indirect addressing mode is
assumed.
For ST7 devices, you can also use.b to specify short indirect addressing mode (as with the
indexed addressing mode).
lab08 ld A,#1 ; load A with immediate value 1
lab09 bset memory,#3 ; set bit #3 in memory location
btjt memory,#3,label ; test bit #3 of memory and
jump if true (set)
ld A,[80] ; short indirect
ld A,[80.b] ; short indirect
ld A,[80.w] ; long indirect
lab12 equ 80
ld A,([lab12],X) ; short indirect X-indexed
ld A,([lab12.b],X) ; short indirect X-indexed
ld A,([lab12.w],Y) ; long indirect Y-indexed