0d832e7f5e
PR 25690 * config/tc-z80.c (md_pseudo_table): Add xdef anf xref pseudo ops. * doc/c-z80.texi: Update documentation.
373 lines
13 KiB
Plaintext
373 lines
13 KiB
Plaintext
@c Copyright (C) 2011-2020 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 Z80-Dependent
|
|
@chapter Z80 Dependent Features
|
|
@end ifset
|
|
|
|
|
|
@ifclear GENERIC
|
|
@node Machine Dependencies
|
|
@chapter Z80 Dependent Features
|
|
@end ifclear
|
|
|
|
@cindex Z80 support
|
|
@menu
|
|
* Z80 Options:: Options
|
|
* Z80 Syntax:: Syntax
|
|
* Z80 Floating Point:: Floating Point
|
|
* Z80 Directives:: Z80 Machine Directives
|
|
* Z80 Opcodes:: Opcodes
|
|
@end menu
|
|
|
|
@node Z80 Options
|
|
@section Command-line Options
|
|
@cindex Z80 options
|
|
@cindex options for Z80
|
|
@c man begin OPTIONS
|
|
@table @gcctabopt
|
|
|
|
@cindex @code{-march=} command-line option, Z80
|
|
@item -march=@var{CPU}[-@var{EXT}@dots{}][+@var{EXT}@dots{}]
|
|
This option specifies the target processor. The assembler will issue
|
|
an error message if an attempt is made to assemble an instruction which
|
|
will not execute on the target processor. The following processor names
|
|
are recognized:
|
|
@code{z80},
|
|
@code{z180},
|
|
@code{ez80},
|
|
@code{gbz80},
|
|
@code{z80n},
|
|
@code{r800}.
|
|
In addition to the basic instruction set, the assembler can be told to
|
|
accept some extention mnemonics. For example,
|
|
@code{-march=z180+sli+infc} extends @var{z180} with @var{SLI} instructions and
|
|
@var{IN F,(C)}. The following extentions are currently supported:
|
|
@code{full} (all known instructions),
|
|
@code{adl} (ADL CPU mode by default, eZ80 only),
|
|
@code{sli} (instruction known as @var{SLI}, @var{SLL} or @var{SL1}),
|
|
@code{xyhl} (instructions with halves of index registers: @var{IXL}, @var{IXH},
|
|
@var{IYL}, @var{IYH}),
|
|
@code{xdcb} (instructions like @var{RotOp (II+d),R} and @var{BitOp n,(II+d),R}),
|
|
@code{infc} (instruction @var{IN F,(C)} or @var{IN (C)}),
|
|
@code{outc0} (instruction @var{OUT (C),0}).
|
|
Note that rather than extending a basic instruction set, the extention
|
|
mnemonics starting with @code{-} revoke the respective functionality:
|
|
@code{-march=z80-full+xyhl} first removes all default extentions and adds
|
|
support for index registers halves only.
|
|
|
|
If this option is not specified then @code{-march=z80+xyhl+infc} is assumed.
|
|
|
|
@cindex @code{-local-prefix} command-line option, Z80
|
|
@item -local-prefix=@var{prefix}
|
|
Mark all labels with specified prefix as local. But such label can be
|
|
marked global explicitly in the code. This option do not change default
|
|
local label prefix @code{.L}, it is just adds new one.
|
|
|
|
@cindex @code{-colonless} command-line option, Z80
|
|
@item -colonless
|
|
Accept colonless labels. All symbols at line begin are treated as labels.
|
|
|
|
@cindex @code{-sdcc} command-line option, Z80
|
|
@item -sdcc
|
|
Accept assembler code produced by SDCC.
|
|
|
|
@cindex @code{-fp-s} command-line option, Z80
|
|
@item -fp-s=@var{FORMAT}
|
|
Single precision floating point numbers format. Default: ieee754 (32 bit).
|
|
|
|
@cindex @code{-fp-d} command-line option, Z80
|
|
@item -fp-d=@var{FORMAT}
|
|
Double precision floating point numbers format. Default: ieee754 (64 bit).
|
|
@end table
|
|
@c man end
|
|
|
|
Floating point numbers formats.
|
|
@table @option
|
|
@item @code{ieee754}
|
|
Single or double precision IEEE754 compatible format.
|
|
|
|
@item @code{half}
|
|
Half precision IEEE754 compatible format (16 bits).
|
|
|
|
@item @code{single}
|
|
Single precision IEEE754 compatible format (32 bits).
|
|
|
|
@item @code{double}
|
|
Double precision IEEE754 compatible format (64 bits).
|
|
|
|
@item @code{zeda32}
|
|
32 bit floating point format from z80float library by Zeda.
|
|
|
|
@item @code{math48}
|
|
48 bit floating point format from Math48 package by Anders Hejlsberg.
|
|
@end table
|
|
|
|
@cindex Z80 Syntax
|
|
@node Z80 Syntax
|
|
@section Syntax
|
|
The assembler syntax closely follows the 'Z80 family CPU User Manual' by
|
|
Zilog.
|
|
In expressions a single @samp{=} may be used as ``is equal to''
|
|
comparison operator.
|
|
|
|
Suffices can be used to indicate the radix of integer constants;
|
|
@samp{H} or @samp{h} for hexadecimal, @samp{D} or @samp{d} for decimal,
|
|
@samp{Q}, @samp{O}, @samp{q} or @samp{o} for octal, and @samp{B} for
|
|
binary.
|
|
|
|
The suffix @samp{b} denotes a backreference to local label.
|
|
|
|
@menu
|
|
* Z80-Chars:: Special Characters
|
|
* Z80-Regs:: Register Names
|
|
* Z80-Case:: Case Sensitivity
|
|
* Z80-Labels:: Labels
|
|
@end menu
|
|
|
|
@node Z80-Chars
|
|
@subsection Special Characters
|
|
|
|
@cindex line comment character, Z80
|
|
@cindex Z80 line comment character
|
|
The semicolon @samp{;} is the line comment character;
|
|
|
|
If a @samp{#} appears as the first character of a line then the whole
|
|
line is treated as a comment, but in this case the line could also be
|
|
a logical line number directive (@pxref{Comments}) or a preprocessor
|
|
control command (@pxref{Preprocessing}).
|
|
|
|
@cindex line separator, Z80
|
|
@cindex statement separator, Z80
|
|
@cindex Z80 line separator
|
|
The Z80 assembler does not support a line separator character.
|
|
|
|
@cindex location counter, Z80
|
|
@cindex hexadecimal prefix, Z80
|
|
@cindex Z80 $
|
|
The dollar sign @samp{$} can be used as a prefix for hexadecimal numbers
|
|
and as a symbol denoting the current location counter.
|
|
|
|
@cindex character escapes, Z80
|
|
@cindex Z80, \
|
|
A backslash @samp{\} is an ordinary character for the Z80 assembler.
|
|
|
|
@cindex character constant, Z80
|
|
@cindex single quote, Z80
|
|
@cindex Z80 '
|
|
The single quote @samp{'} must be followed by a closing quote. If there
|
|
is one character in between, it is a character constant, otherwise it is
|
|
a string constant.
|
|
|
|
@node Z80-Regs
|
|
@subsection Register Names
|
|
@cindex Z80 registers
|
|
@cindex register names, Z80
|
|
|
|
The registers are referred to with the letters assigned to them by
|
|
Zilog. In addition @command{@value{AS}} recognizes @samp{ixl} and
|
|
@samp{ixh} as the least and most significant octet in @samp{ix}, and
|
|
similarly @samp{iyl} and @samp{iyh} as parts of @samp{iy}.
|
|
|
|
@c The @samp{'} in @samp{ex af,af'} may be omitted.
|
|
|
|
@node Z80-Case
|
|
@subsection Case Sensitivity
|
|
@cindex Z80, case sensitivity
|
|
@cindex case sensitivity, Z80
|
|
|
|
Upper and lower case are equivalent in register names, opcodes,
|
|
condition codes and assembler directives.
|
|
The case of letters is significant in labels and symbol names. The case
|
|
is also important to distinguish the suffix @samp{b} for a backward reference
|
|
to a local label from the suffix @samp{B} for a number in binary notation.
|
|
|
|
@node Z80-Labels
|
|
@subsection Labels
|
|
|
|
@cindex labels, Z80
|
|
@cindex Z80 labels
|
|
Labels started by @code{.L} acts as local labels. You may specify custom local
|
|
label prefix by @code{-local-prefix} command-line option.
|
|
Dollar, forward and backward local labels are supported. By default, all labels
|
|
are followed by colon.
|
|
Legacy code with colonless labels can be built with @code{-colonless}
|
|
command-line option specified. In this case all tokens at line begin are treated
|
|
as labels.
|
|
|
|
@node Z80 Floating Point
|
|
@section Floating Point
|
|
@cindex floating point, Z80
|
|
@cindex Z80 floating point
|
|
Floating-point numbers of following types are supported:
|
|
|
|
@table @option
|
|
@item @code{ieee754}
|
|
Supported half, single and double precision IEEE754 compatible numbers.
|
|
|
|
@item @code{zeda32}
|
|
32 bit floating point numbers from z80float library by Zeda.
|
|
|
|
@item @code{math48}
|
|
48 bit floating point numbers from Math48 package by Anders Hejlsberg.
|
|
@end table
|
|
|
|
@node Z80 Directives
|
|
@section Z80 Assembler Directives
|
|
@cindex Z80-only directives
|
|
|
|
@command{@value{AS}} for the Z80 supports some additional directives for
|
|
compatibility with other assemblers.
|
|
|
|
These are the additional directives in @code{@value{AS}} for the Z80:
|
|
|
|
@table @code
|
|
@item @code{.assume ADL = @var{expression}}
|
|
@cindex @code{.assume} directive, Z80
|
|
Set ADL status for eZ80. Non-zero value enable compilation in ADL mode else
|
|
used Z80 mode. ADL and Z80 mode produces incompatible object code. Mixing
|
|
both of them within one binary may lead problems with disassembler.
|
|
|
|
@item @code{db @var{expression}|@var{string}[,@var{expression}|@var{string}...]}
|
|
@cindex @code{db} directive, Z80
|
|
@itemx @code{defb @var{expression}|@var{string}[,@var{expression}|@var{string}...]}
|
|
@cindex @code{defb} directive, Z80
|
|
@itemx @code{defm @var{string}[,@var{string}...]}
|
|
@cindex @code{defm} directive, Z80
|
|
For each @var{string} the characters are copied to the object file, for
|
|
each other @var{expression} the value is stored in one byte.
|
|
A warning is issued in case of an overflow.
|
|
Backslash symbol in the strings is generic symbol, it cannot be used as
|
|
escape character (@xref{Ascii,,@code{.ascii}}).
|
|
|
|
@item @code{dw @var{expression}[,@var{expression}...]}
|
|
@cindex @code{dw} directive, Z80
|
|
@itemx @code{defw @var{expression}[,@var{expression}...]}
|
|
@cindex @code{defw} directive, Z80
|
|
For each @var{expression} the value is stored in two bytes, ignoring
|
|
overflow.
|
|
|
|
@item @code{d24 @var{expression}[,@var{expression}...]}
|
|
@cindex @code{d24} directive, Z80
|
|
@itemx @code{def24 @var{expression}[,@var{expression}...]}
|
|
@cindex @code{def24} directive, Z80
|
|
For each @var{expression} the value is stored in three bytes, ignoring
|
|
overflow.
|
|
|
|
@item @code{d32 @var{expression}[,@var{expression}...]}
|
|
@cindex @code{d32} directive, Z80
|
|
@itemx @code{def32 @var{expression}[,@var{expression}...]}
|
|
@cindex @code{def32} directive, Z80
|
|
For each @var{expression} the value is stored in four bytes, ignoring
|
|
overflow.
|
|
|
|
@item @code{ds @var{count}[, @var{value}]}
|
|
@cindex @code{ds} directive, Z80
|
|
@itemx @code{defs @var{count}[, @var{value}]}
|
|
@cindex @code{defs} directive, Z80
|
|
@c Synonyms for @code{ds.b},
|
|
@c which should have been described elsewhere
|
|
Fill @var{count} bytes in the object file with @var{value}, if
|
|
@var{value} is omitted it defaults to zero.
|
|
|
|
@item @code{@var{symbol} defl @var{expression}}
|
|
@cindex @code{defl} directive, Z80
|
|
The @code{defl} directive is like @code{.set} but with different syntax (@xref{Set,,@code{.set}}).
|
|
It set the value of @var{symbol} to @var{expression}. Symbols defined
|
|
with @code{defl} are not protected from redefinition.
|
|
|
|
@item @code{@var{symbol} equ @var{expression}}
|
|
@cindex @code{equ} directive, Z80
|
|
The @code{equ} directive is like @code{.equiv} but with different syntax (@xref{Equiv,,@code{.equiv}}).
|
|
It set the value of @var{symbol} to @var{expression}. It is an error
|
|
if @var{symbol} is already defined. Symbols defined with @code{equ}
|
|
are not protected from redefinition.
|
|
|
|
@item @code{psect @var{name}}
|
|
@cindex @code{psect} directive, Z80
|
|
A synonym for @code{.section}, no second argument should be given (@xref{Section,,@code{.section}}).
|
|
|
|
@item @code{xdef @var{symbol}}
|
|
@cindex @code{xdef} directive, Z80
|
|
A synonym for @code{.global}, make @var{symbol} is visible to linker (@xref{Global,,@code{.global}}).
|
|
|
|
@item @code{xref @var{name}}
|
|
@cindex @code{xref} directive, Z80
|
|
A synonym for @code{.extern} (@ref{Extern,,@code{.extern}}).
|
|
@ignore
|
|
|
|
The following attributes will possibly be recognized in the future
|
|
@table @code
|
|
@item abs
|
|
The section is to be absolute. @code{@value{AS}} will issue an error
|
|
message because it can not produce an absolute section.
|
|
@item global
|
|
The section is to be concatenated with other sections of the same name
|
|
by the linker, this is the default.
|
|
@item local
|
|
The section is not global. @code{@value{AS}} will issue a warning if
|
|
object file format is not soff.
|
|
@item ovrld
|
|
The section is to be overlapped with other sections of the same name by
|
|
the linker. @code{@value{AS}} will issue an error message
|
|
because it can not mark a section as such.
|
|
@item pure
|
|
The section is marked as read only.
|
|
@end table
|
|
@end ignore
|
|
|
|
@end table
|
|
|
|
@node Z80 Opcodes
|
|
@section Opcodes
|
|
In line with common practice, Z80 mnemonics are used for the Z80,
|
|
Z80N, Z180, eZ80, Ascii R800 and the GameBoy Z80.
|
|
|
|
In many instructions it is possible to use one of the half index
|
|
registers (@samp{ixl},@samp{ixh},@samp{iyl},@samp{iyh}) in stead of an
|
|
8-bit general purpose register. This yields instructions that are
|
|
documented on the eZ80 and the R800, undocumented on the Z80 and
|
|
unsupported on the Z180.
|
|
Similarly @code{in f,(c)} is documented on the R800, undocumented on
|
|
the Z80 and unsupported on the Z180 and the eZ80.
|
|
|
|
The assembler also supports the following undocumented Z80-instructions,
|
|
that have not been adopted in any other instruction set:
|
|
@table @code
|
|
@item out (c),0
|
|
Sends zero to the port pointed to by register @code{C}.
|
|
|
|
@item sli @var{m}
|
|
Equivalent to @code{@var{m} = (@var{m}<<1)+1}, the operand @var{m} can
|
|
be any operand that is valid for @samp{sla}. One can use @samp{sll} as a
|
|
synonym for @samp{sli}.
|
|
|
|
@item @var{op} (ix+@var{d}), @var{r}
|
|
This is equivalent to
|
|
|
|
@example
|
|
ld @var{r}, (ix+@var{d})
|
|
@var{op} @var{r}
|
|
ld (ix+@var{d}), @var{r}
|
|
@end example
|
|
|
|
The operation @samp{@var{op}} may be any of @samp{res @var{b},},
|
|
@samp{set @var{b},}, @samp{rl}, @samp{rlc}, @samp{rr}, @samp{rrc},
|
|
@samp{sla}, @samp{sli}, @samp{sra} and @samp{srl}, and the register
|
|
@samp{@var{r}} may be any of @samp{a}, @samp{b}, @samp{c}, @samp{d},
|
|
@samp{e}, @samp{h} and @samp{l}.
|
|
|
|
@item @var{op} (iy+@var{d}), @var{r}
|
|
As above, but with @samp{iy} instead of @samp{ix}.
|
|
@end table
|
|
|
|
The web site at @uref{http://www.z80.info} is a good starting place to
|
|
find more information on programming the Z80.
|
|
|
|
You may enable or disable any of these instructions for any target CPU
|
|
even this instruction is not supported by any real CPU of this type.
|
|
Useful for custom CPU cores.
|