source: trunk/binutils/gas/doc/c-msp430.texi@ 2723

@c Copyright 2002 Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
@ifset GENERIC
@page
@node MSP430-Dependent
@chapter MSP 430 Dependent Features
@end ifset
@ifclear GENERIC
@node Machine Dependencies
@chapter MSP 430 Dependent Features
@end ifclear

@cindex MSP 430 support
@cindex 430 support
@menu
* MSP430 Options::              Options
* MSP430 Syntax::               Syntax
* MSP430 Floating Point::       Floating Point
* MSP430 Directives::           MSP 430 Machine Directives
* MSP430 Opcodes::              Opcodes
@end menu

@node MSP430 Options
@section Options
@cindex MSP 430 options (none)
@cindex options for MSP430 (none)
@code{@value{AS}} has only -m flag which selects the mpu arch. Currently has 
no effect.

@node MSP430 Syntax
@section Syntax
@menu
* MSP430-Macros::               Macros
* MSP430-Chars::                Special Characters
* MSP430-Regs::                 Register Names
* MSP430-Ext::                  Assembler Extensions
@end menu

@node MSP430-Macros
@subsection Macros

@cindex Macros, MSP 430
@cindex MSP 430 macros
The macro syntax used on the MSP 430 is like that described in the MSP
430 Family Assembler Specification.  Normal @code{@value{AS}}
macros should still work.

Additional built-in macros are:

@table @code

@item llo(exp) 
Extracts least significant word from 32-bit expression 'exp'.

@item lhi(exp)
Extracts most significant word from 32-bit expression 'exp'.

@item hlo(exp)
Extracts 3rd word from 64-bit expression 'exp'.

@item   hhi(exp) 
Extracts 4rd word from 64-bit expression 'exp'.

@end table

They normally being used as an immediate source operand.
@smallexample
    mov #llo(1), r10    ;       == mov  #1, r10 
    mov #lhi(1), r10    ;       == mov  #0, r10
@end smallexample
        
@node MSP430-Chars
@subsection Special Characters

@cindex line comment character, MSP 430
@cindex MSP 430 line comment character
@samp{;} is the line comment character.

@cindex identifiers, MSP 430
@cindex MSP 430 identifiers
The character @samp{$} in jump instructions indicates current location and 
implemented only for TI syntax compatibility.

@node MSP430-Regs
@subsection Register Names

@cindex MSP 430 register names
@cindex register names, MSP 430
General-purpose registers are represented by predefined symbols of the
form @samp{r@var{N}} (for global registers), where @var{N} represents
a number between @code{0} and @code{15}.  The leading
letters may be in either upper or lower case; for example, @samp{r13}
and @samp{R7} are both valid register names.

@cindex special purpose registers, MSP 430
Register names @samp{PC}, @samp{SP} and @samp{SR} cannot be used as register names
and will be treated as variables. Use @samp{r0}, @samp{r1}, and @samp{r2} instead.


@node MSP430-Ext
@subsection Assembler Extensions
@cindex MSP430 Assembler Extensions

@table @code

@item @@rN
As destination operand being treated as @samp{0(rn)}

@item 0(rN)
As source operand being treated as @samp{@@rn}

@item jCOND +N
Skips next N bytes followed by jump instruction and equivalent to
@samp{jCOND $+N+2}

@end table


@node MSP430 Floating Point
@section Floating Point

@cindex floating point, MSP 430 (@sc{ieee})
@cindex MSP 430 floating point (@sc{ieee})
The MSP 430 family uses @sc{ieee} 32-bit floating-point numbers.

@node MSP430 Directives
@section MSP 430 Machine Directives

@cindex machine directives, MSP 430
@cindex MSP 430 machine directives
@table @code
@cindex @code{file} directive, MSP 430
@item .file
This directive is ignored; it is accepted for compatibility with other
MSP 430 assemblers.

@quotation
@emph{Warning:} in other versions of the @sc{gnu} assembler, @code{.file} is
used for the directive called @code{.app-file} in the MSP 430 support.
@end quotation

@cindex @code{line} directive, MSP 430
@item .line
This directive is ignored; it is accepted for compatibility with other
MSP 430 assemblers.

@cindex @code{sect} directive, MSP 430
@item .arch
Currently this directive is ignored; it is accepted for compatibility with other
MSP 430 assemblers.

@end table

@node MSP430 Opcodes
@section Opcodes

@cindex MSP 430 opcodes
@cindex opcodes for MSP 430
@code{@value{AS}} implements all the standard MSP 430 opcodes.  No
additional pseudo-instructions are needed on this family.

For information on the 430 machine instruction set, see @cite{MSP430
User's Manual, document slau049b}, Texas Instrument, Inc.