mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-11-24 18:44:20 +08:00
443 lines
14 KiB
Plaintext
443 lines
14 KiB
Plaintext
@c Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000, 2003, 2006
|
|
@c 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 M68HC11-Dependent
|
|
@chapter M68HC11 and M68HC12 Dependent Features
|
|
@end ifset
|
|
@ifclear GENERIC
|
|
@node Machine Dependencies
|
|
@chapter M68HC11 and M68HC12 Dependent Features
|
|
@end ifclear
|
|
|
|
@cindex M68HC11 and M68HC12 support
|
|
@menu
|
|
* M68HC11-Opts:: M68HC11 and M68HC12 Options
|
|
* M68HC11-Syntax:: Syntax
|
|
* M68HC11-Modifiers:: Symbolic Operand Modifiers
|
|
* M68HC11-Directives:: Assembler Directives
|
|
* M68HC11-Float:: Floating Point
|
|
* M68HC11-opcodes:: Opcodes
|
|
@end menu
|
|
|
|
@node M68HC11-Opts
|
|
@section M68HC11 and M68HC12 Options
|
|
|
|
@cindex options, M68HC11
|
|
@cindex M68HC11 options
|
|
The Motorola 68HC11 and 68HC12 version of @code{@value{AS}} have a few machine
|
|
dependent options.
|
|
|
|
@table @code
|
|
|
|
@cindex @samp{-m68hc11}
|
|
@item -m68hc11
|
|
This option switches the assembler in the M68HC11 mode. In this mode,
|
|
the assembler only accepts 68HC11 operands and mnemonics. It produces
|
|
code for the 68HC11.
|
|
|
|
@cindex @samp{-m68hc12}
|
|
@item -m68hc12
|
|
This option switches the assembler in the M68HC12 mode. In this mode,
|
|
the assembler also accepts 68HC12 operands and mnemonics. It produces
|
|
code for the 68HC12. A few 68HC11 instructions are replaced by
|
|
some 68HC12 instructions as recommended by Motorola specifications.
|
|
|
|
@cindex @samp{-m68hcs12}
|
|
@item -m68hcs12
|
|
This option switches the assembler in the M68HCS12 mode. This mode is
|
|
similar to @samp{-m68hc12} but specifies to assemble for the 68HCS12
|
|
series. The only difference is on the assembling of the @samp{movb}
|
|
and @samp{movw} instruction when a PC-relative operand is used.
|
|
|
|
@cindex @samp{-mshort}
|
|
@item -mshort
|
|
This option controls the ABI and indicates to use a 16-bit integer ABI.
|
|
It has no effect on the assembled instructions.
|
|
This is the default.
|
|
|
|
@cindex @samp{-mlong}
|
|
@item -mlong
|
|
This option controls the ABI and indicates to use a 32-bit integer ABI.
|
|
|
|
@cindex @samp{-mshort-double}
|
|
@item -mshort-double
|
|
This option controls the ABI and indicates to use a 32-bit float ABI.
|
|
This is the default.
|
|
|
|
@cindex @samp{-mlong-double}
|
|
@item -mlong-double
|
|
This option controls the ABI and indicates to use a 64-bit float ABI.
|
|
|
|
@cindex @samp{--strict-direct-mode}
|
|
@item --strict-direct-mode
|
|
You can use the @samp{--strict-direct-mode} option to disable
|
|
the automatic translation of direct page mode addressing into
|
|
extended mode when the instruction does not support direct mode.
|
|
For example, the @samp{clr} instruction does not support direct page
|
|
mode addressing. When it is used with the direct page mode,
|
|
@code{@value{AS}} will ignore it and generate an absolute addressing.
|
|
This option prevents @code{@value{AS}} from doing this, and the wrong
|
|
usage of the direct page mode will raise an error.
|
|
|
|
@cindex @samp{--short-branches}
|
|
@item --short-branches
|
|
The @samp{--short-branches} option turns off the translation of
|
|
relative branches into absolute branches when the branch offset is
|
|
out of range. By default @code{@value{AS}} transforms the relative
|
|
branch (@samp{bsr}, @samp{bgt}, @samp{bge}, @samp{beq}, @samp{bne},
|
|
@samp{ble}, @samp{blt}, @samp{bhi}, @samp{bcc}, @samp{bls},
|
|
@samp{bcs}, @samp{bmi}, @samp{bvs}, @samp{bvs}, @samp{bra}) into
|
|
an absolute branch when the offset is out of the -128 .. 127 range.
|
|
In that case, the @samp{bsr} instruction is translated into a
|
|
@samp{jsr}, the @samp{bra} instruction is translated into a
|
|
@samp{jmp} and the conditional branches instructions are inverted and
|
|
followed by a @samp{jmp}. This option disables these translations
|
|
and @code{@value{AS}} will generate an error if a relative branch
|
|
is out of range. This option does not affect the optimization
|
|
associated to the @samp{jbra}, @samp{jbsr} and @samp{jbXX} pseudo opcodes.
|
|
|
|
@cindex @samp{--force-long-branches}
|
|
@item --force-long-branches
|
|
The @samp{--force-long-branches} option forces the translation of
|
|
relative branches into absolute branches. This option does not affect
|
|
the optimization associated to the @samp{jbra}, @samp{jbsr} and
|
|
@samp{jbXX} pseudo opcodes.
|
|
|
|
@cindex @samp{--print-insn-syntax}
|
|
@item --print-insn-syntax
|
|
You can use the @samp{--print-insn-syntax} option to obtain the
|
|
syntax description of the instruction when an error is detected.
|
|
|
|
@cindex @samp{--print-opcodes}
|
|
@item --print-opcodes
|
|
The @samp{--print-opcodes} option prints the list of all the
|
|
instructions with their syntax. The first item of each line
|
|
represents the instruction name and the rest of the line indicates
|
|
the possible operands for that instruction. The list is printed
|
|
in alphabetical order. Once the list is printed @code{@value{AS}}
|
|
exits.
|
|
|
|
@cindex @samp{--generate-example}
|
|
@item --generate-example
|
|
The @samp{--generate-example} option is similar to @samp{--print-opcodes}
|
|
but it generates an example for each instruction instead.
|
|
@end table
|
|
|
|
@node M68HC11-Syntax
|
|
@section Syntax
|
|
|
|
@cindex M68HC11 syntax
|
|
@cindex syntax, M68HC11
|
|
|
|
In the M68HC11 syntax, the instruction name comes first and it may
|
|
be followed by one or several operands (up to three). Operands are
|
|
separated by comma (@samp{,}). In the normal mode,
|
|
@code{@value{AS}} will complain if too many operands are specified for
|
|
a given instruction. In the MRI mode (turned on with @samp{-M} option),
|
|
it will treat them as comments. Example:
|
|
|
|
@smallexample
|
|
inx
|
|
lda #23
|
|
bset 2,x #4
|
|
brclr *bot #8 foo
|
|
@end smallexample
|
|
|
|
@cindex M68HC11 addressing modes
|
|
@cindex addressing modes, M68HC11
|
|
The following addressing modes are understood for 68HC11 and 68HC12:
|
|
@table @dfn
|
|
@item Immediate
|
|
@samp{#@var{number}}
|
|
|
|
@item Address Register
|
|
@samp{@var{number},X}, @samp{@var{number},Y}
|
|
|
|
The @var{number} may be omitted in which case 0 is assumed.
|
|
|
|
@item Direct Addressing mode
|
|
@samp{*@var{symbol}}, or @samp{*@var{digits}}
|
|
|
|
@item Absolute
|
|
@samp{@var{symbol}}, or @samp{@var{digits}}
|
|
@end table
|
|
|
|
The M68HC12 has other more complex addressing modes. All of them
|
|
are supported and they are represented below:
|
|
|
|
@table @dfn
|
|
@item Constant Offset Indexed Addressing Mode
|
|
@samp{@var{number},@var{reg}}
|
|
|
|
The @var{number} may be omitted in which case 0 is assumed.
|
|
The register can be either @samp{X}, @samp{Y}, @samp{SP} or
|
|
@samp{PC}. The assembler will use the smaller post-byte definition
|
|
according to the constant value (5-bit constant offset, 9-bit constant
|
|
offset or 16-bit constant offset). If the constant is not known by
|
|
the assembler it will use the 16-bit constant offset post-byte and the value
|
|
will be resolved at link time.
|
|
|
|
@item Offset Indexed Indirect
|
|
@samp{[@var{number},@var{reg}]}
|
|
|
|
The register can be either @samp{X}, @samp{Y}, @samp{SP} or @samp{PC}.
|
|
|
|
@item Auto Pre-Increment/Pre-Decrement/Post-Increment/Post-Decrement
|
|
@samp{@var{number},-@var{reg}}
|
|
@samp{@var{number},+@var{reg}}
|
|
@samp{@var{number},@var{reg}-}
|
|
@samp{@var{number},@var{reg}+}
|
|
|
|
The number must be in the range @samp{-8}..@samp{+8} and must not be 0.
|
|
The register can be either @samp{X}, @samp{Y}, @samp{SP} or @samp{PC}.
|
|
|
|
@item Accumulator Offset
|
|
@samp{@var{acc},@var{reg}}
|
|
|
|
The accumulator register can be either @samp{A}, @samp{B} or @samp{D}.
|
|
The register can be either @samp{X}, @samp{Y}, @samp{SP} or @samp{PC}.
|
|
|
|
@item Accumulator D offset indexed-indirect
|
|
@samp{[D,@var{reg}]}
|
|
|
|
The register can be either @samp{X}, @samp{Y}, @samp{SP} or @samp{PC}.
|
|
|
|
@end table
|
|
|
|
For example:
|
|
|
|
@smallexample
|
|
ldab 1024,sp
|
|
ldd [10,x]
|
|
orab 3,+x
|
|
stab -2,y-
|
|
ldx a,pc
|
|
sty [d,sp]
|
|
@end smallexample
|
|
|
|
|
|
@node M68HC11-Modifiers
|
|
@section Symbolic Operand Modifiers
|
|
|
|
@cindex M68HC11 modifiers
|
|
@cindex syntax, M68HC11
|
|
|
|
The assembler supports several modifiers when using symbol addresses
|
|
in 68HC11 and 68HC12 instruction operands. The general syntax is
|
|
the following:
|
|
|
|
@smallexample
|
|
%modifier(symbol)
|
|
@end smallexample
|
|
|
|
@table @code
|
|
@cindex symbol modifiers
|
|
@item %addr
|
|
This modifier indicates to the assembler and linker to use
|
|
the 16-bit physical address corresponding to the symbol. This is intended
|
|
to be used on memory window systems to map a symbol in the memory bank window.
|
|
If the symbol is in a memory expansion part, the physical address
|
|
corresponds to the symbol address within the memory bank window.
|
|
If the symbol is not in a memory expansion part, this is the symbol address
|
|
(using or not using the %addr modifier has no effect in that case).
|
|
|
|
@item %page
|
|
This modifier indicates to use the memory page number corresponding
|
|
to the symbol. If the symbol is in a memory expansion part, its page
|
|
number is computed by the linker as a number used to map the page containing
|
|
the symbol in the memory bank window. If the symbol is not in a memory
|
|
expansion part, the page number is 0.
|
|
|
|
@item %hi
|
|
This modifier indicates to use the 8-bit high part of the physical
|
|
address of the symbol.
|
|
|
|
@item %lo
|
|
This modifier indicates to use the 8-bit low part of the physical
|
|
address of the symbol.
|
|
|
|
@end table
|
|
|
|
For example a 68HC12 call to a function @samp{foo_example} stored in memory
|
|
expansion part could be written as follows:
|
|
|
|
@smallexample
|
|
call %addr(foo_example),%page(foo_example)
|
|
@end smallexample
|
|
|
|
and this is equivalent to
|
|
|
|
@smallexample
|
|
call foo_example
|
|
@end smallexample
|
|
|
|
And for 68HC11 it could be written as follows:
|
|
|
|
@smallexample
|
|
ldab #%page(foo_example)
|
|
stab _page_switch
|
|
jsr %addr(foo_example)
|
|
@end smallexample
|
|
|
|
@node M68HC11-Directives
|
|
@section Assembler Directives
|
|
|
|
@cindex assembler directives, M68HC11
|
|
@cindex assembler directives, M68HC12
|
|
@cindex M68HC11 assembler directives
|
|
@cindex M68HC12 assembler directives
|
|
|
|
The 68HC11 and 68HC12 version of @code{@value{AS}} have the following
|
|
specific assembler directives:
|
|
|
|
@table @code
|
|
@item .relax
|
|
@cindex assembler directive .relax, M68HC11
|
|
@cindex M68HC11 assembler directive .relax
|
|
The relax directive is used by the @samp{GNU Compiler} to emit a specific
|
|
relocation to mark a group of instructions for linker relaxation.
|
|
The sequence of instructions within the group must be known to the linker
|
|
so that relaxation can be performed.
|
|
|
|
@item .mode [mshort|mlong|mshort-double|mlong-double]
|
|
@cindex assembler directive .mode, M68HC11
|
|
@cindex M68HC11 assembler directive .mode
|
|
This directive specifies the ABI. It overrides the @samp{-mshort},
|
|
@samp{-mlong}, @samp{-mshort-double} and @samp{-mlong-double} options.
|
|
|
|
@item .far @var{symbol}
|
|
@cindex assembler directive .far, M68HC11
|
|
@cindex M68HC11 assembler directive .far
|
|
This directive marks the symbol as a @samp{far} symbol meaning that it
|
|
uses a @samp{call/rtc} calling convention as opposed to @samp{jsr/rts}.
|
|
During a final link, the linker will identify references to the @samp{far}
|
|
symbol and will verify the proper calling convention.
|
|
|
|
@item .interrupt @var{symbol}
|
|
@cindex assembler directive .interrupt, M68HC11
|
|
@cindex M68HC11 assembler directive .interrupt
|
|
This directive marks the symbol as an interrupt entry point.
|
|
This information is then used by the debugger to correctly unwind the
|
|
frame across interrupts.
|
|
|
|
@item .xrefb @var{symbol}
|
|
@cindex assembler directive .xrefb, M68HC11
|
|
@cindex M68HC11 assembler directive .xrefb
|
|
This directive is defined for compatibility with the
|
|
@samp{Specification for Motorola 8 and 16-Bit Assembly Language Input
|
|
Standard} and is ignored.
|
|
|
|
@end table
|
|
|
|
@node M68HC11-Float
|
|
@section Floating Point
|
|
|
|
@cindex floating point, M68HC11
|
|
@cindex M68HC11 floating point
|
|
Packed decimal (P) format floating literals are not supported.
|
|
Feel free to add the code!
|
|
|
|
The floating point formats generated by directives are these.
|
|
|
|
@table @code
|
|
@cindex @code{float} directive, M68HC11
|
|
@item .float
|
|
@code{Single} precision floating point constants.
|
|
|
|
@cindex @code{double} directive, M68HC11
|
|
@item .double
|
|
@code{Double} precision floating point constants.
|
|
|
|
@cindex @code{extend} directive M68HC11
|
|
@cindex @code{ldouble} directive M68HC11
|
|
@item .extend
|
|
@itemx .ldouble
|
|
@code{Extended} precision (@code{long double}) floating point constants.
|
|
@end table
|
|
|
|
@need 2000
|
|
@node M68HC11-opcodes
|
|
@section Opcodes
|
|
|
|
@cindex M68HC11 opcodes
|
|
@cindex opcodes, M68HC11
|
|
@cindex instruction set, M68HC11
|
|
|
|
@menu
|
|
* M68HC11-Branch:: Branch Improvement
|
|
@end menu
|
|
|
|
@node M68HC11-Branch
|
|
@subsection Branch Improvement
|
|
|
|
@cindex pseudo-opcodes, M68HC11
|
|
@cindex M68HC11 pseudo-opcodes
|
|
@cindex branch improvement, M68HC11
|
|
@cindex M68HC11 branch improvement
|
|
|
|
Certain pseudo opcodes are permitted for branch instructions.
|
|
They expand to the shortest branch instruction that reach the
|
|
target. Generally these mnemonics are made by prepending @samp{j} to
|
|
the start of Motorola mnemonic. These pseudo opcodes are not affected
|
|
by the @samp{--short-branches} or @samp{--force-long-branches} options.
|
|
|
|
The following table summarizes the pseudo-operations.
|
|
|
|
@smallexample
|
|
Displacement Width
|
|
+-------------------------------------------------------------+
|
|
| Options |
|
|
| --short-branches --force-long-branches |
|
|
+--------------------------+----------------------------------+
|
|
Op |BYTE WORD | BYTE WORD |
|
|
+--------------------------+----------------------------------+
|
|
bsr | bsr <pc-rel> <error> | jsr <abs> |
|
|
bra | bra <pc-rel> <error> | jmp <abs> |
|
|
jbsr | bsr <pc-rel> jsr <abs> | bsr <pc-rel> jsr <abs> |
|
|
jbra | bra <pc-rel> jmp <abs> | bra <pc-rel> jmp <abs> |
|
|
bXX | bXX <pc-rel> <error> | bNX +3; jmp <abs> |
|
|
jbXX | bXX <pc-rel> bNX +3; | bXX <pc-rel> bNX +3; jmp <abs> |
|
|
| jmp <abs> | |
|
|
+--------------------------+----------------------------------+
|
|
XX: condition
|
|
NX: negative of condition XX
|
|
|
|
@end smallexample
|
|
|
|
@table @code
|
|
@item jbsr
|
|
@itemx jbra
|
|
These are the simplest jump pseudo-operations; they always map to one
|
|
particular machine instruction, depending on the displacement to the
|
|
branch target.
|
|
|
|
@item jb@var{XX}
|
|
Here, @samp{jb@var{XX}} stands for an entire family of pseudo-operations,
|
|
where @var{XX} is a conditional branch or condition-code test. The full
|
|
list of pseudo-ops in this family is:
|
|
@smallexample
|
|
jbcc jbeq jbge jbgt jbhi jbvs jbpl jblo
|
|
jbcs jbne jblt jble jbls jbvc jbmi
|
|
@end smallexample
|
|
|
|
For the cases of non-PC relative displacements and long displacements,
|
|
@code{@value{AS}} issues a longer code fragment in terms of
|
|
@var{NX}, the opposite condition to @var{XX}. For example, for the
|
|
non-PC relative case:
|
|
@smallexample
|
|
jb@var{XX} foo
|
|
@end smallexample
|
|
gives
|
|
@smallexample
|
|
b@var{NX}s oof
|
|
jmp foo
|
|
oof:
|
|
@end smallexample
|
|
|
|
@end table
|
|
|
|
|