EmuZWin built-in ZX Assembler
supported operators and directives.

(Ñ) by Vladimir Kladov, 2003-2006

Starting from v2.2, it is possible to view entire list of all operators and directives, supported by the built-in ZX Assembler, directly in assembler window.

Source code should satisfy following rules to be compiled correctly.

Following directives and assembler statements are supported by the internal assembler. (Character '#' used to note that an operand could be of any numeric expression allowed). Since in most cases the operator can be continued on the next line, only directives are noted which have some restrictions to this rule.

ORG ENTRYPOINT EQU x=y .=y, $=y ENUM DEFINE DEFB DEFM DEFW DEFS
DEFG DEFD ENCODE CTEXT FILE INCLUDE MACRO ERROR DISPLAY PROC DUP
FOR IF IFcond LOOP BREAK CONTINUE GOTO PUSH POP POPNOINVERT POPINVERT
END                    

ORG [{ RAMn | ROMn },] #target_address [, #dest_address ]
Defines target assembling address and target output destination address.
RAMn and ROMn is used to define RAM bank (n=0..7) or ROM bank (n=0..1).
If distinct dest_address is defined, compiled bytes are put to that address,
though a code itself is compiled for target_address.
All the labels and variables used in the expression must be known on the 
first pass ofthe compiling process (i.e. forward references are not allowed, 
except you turned Strong Address Control option in the assembler off).
 
ENTRYPOINT #expr
Defines entry point to set PC automatically when code compiled OK.
 
label[:] EQU #expression
Defines constant label equal to given expression. label must be unique.
 
label[:] = #expression
Defines variable label equal to given expression. It is possible to 
redefine it with '=' directive any times in the code. Variables can 
be used in any expressions as usual for labels.
Note: after each compilation pass, such variables still save the last
assigned value. This can be used for some calculations on the second
or the third pass, when the code is generated finally.
 
. = #expression
or
$ = #expression
Special form of assignment, using current compiling address as a left
part of the assignment. In result, following code will be compiling
from the address specified by the expression. All the labels and 
variables used in the expression must be known on the first pass of
the compiling process (i.e. forward references are not allowed as like
as for ORG, except you turned Strong Address Control option in the 
assembler off). The main difference to ORG directive is that this address 
will not be put into a list of labels to switch PC address.
 
ENUM label1[=#expr1][,label2[=#expr2]]...
Creates a number of constants label1, label2, ... If expr2, expr3, etc.
are omitted, following constants are assigned to the previous ones incremented
by 1. If the expr1 is omitted, by default the value 0 is used.
 
label[:] DEFINE any text to the end of line
About usage of macro parameters, identifiers defined with DEFINE or variable of
the FOR preprocessor loop see below.
 
DEFB [[(#repeat_count1)]{#expr1|'string1'|?}][,[(#repeat_count2)][{#expr2|'string2'}]]...
a list of bytes. For a string, for each character a single byte is
generated always. If ENCODE directive have defined encoding, all characters
are encoded before put it into memory. By default, DEFB 'abc',0 will be 
compiled to 4 bytes 61h,62h,63h,0. If (repeat_count) is defined for a value 
or string it is repeated repeat_count times (if 0 or less, it is not generated 
at all).
If the symbol '?' is used, correspondent memory is not initialized and
is skip while generating code.
 
DEFM[{ #expression | 'string' }] [, [{ #expression | 'string' }] ]...
a list of bytes. For a string, for each character a single byte is
generated always. The difference to DEFB is that the code for the last character 
of each string constant has the bit 7 set on. 
So, DEFM 'abc' will be compiled to 4 bytes 
61h,62h,E3h.
 
DEFW [[(#repeat_count1)]{#expr1}][,[(#repeat_count2)][{#expr2}]]...
a list of 16-bit words. Very similar to DEFB, but for each value 2 bytes
of memory are initialized (as usual, less significant byte if first - LSB).
 
DEFS #repeat_count [, { #expression | 'string' | "string" } ]...

a list of bytes like for DEFB but entire list of values generated 
#repeat_count times. The same as DUP #repeat_count DEFB list EDUP
If only #repeat_count present without values, 0 is compiled 
#repeat_count times.
 
DEFG ssssssss [ ssssssss ]... 

Special (new) directive to define binary bytes. s = '.' to represent 0, 
any other character to represent 1. Spaces used to separate bytes up to
the end of the line. But numbers are treated as bytes (though those should
be separated with spaces only). If the following line starts from '.', 'x'
or 'X' it is supposed that DEFG allocates several lines, and bytes are 
placed into memory by columns. This directive can be useful to "draw" fonts 
in the source code directly, e.g.:

DEFG ........ .X......
DEFG .XXXXX.. .X......
DEFG ......X. .XXXXX..
DEFG ..XXXXX. .X....X.
DEFG .X....X. .X....X.
DEFG ..XXXX.X .XXXXX..
DEFG ........ ........
(this is a compiled to 0,40h,7Ch,40h,etc.)
or:
DEFG ........ .X......
     .XXXXX.. .X......
     ......X. .XXXXX..
     ..XXXXX. .X....X.
     .X....X. .X....X.
     ..XXXX.X .XXXXX..
     ........ ........
(in this case bytes are: 0,7Ch,2,3Eh,42h,3Dh,0,40h,etc. i.e. bytes 
are placed by columns).
 
DEFD xxxxxx [[,] xxxxxx ]... 

Directive to define packed hexadecimal. E.g. DEFD 1234567890 is the same
as DEFB 12h,34h,56h,78h,90h. If an item an the list is not started with
hexadecimal digit it is evaluated as usual expression. If comma not used,
the directive ends when the next item is not started from hexadecimal 
digit. 
 
ENCODE #from1,#to1[,#from,#to]...

Special directive to encode characters in strings into a desired encoding
(e.g. Russian or other national characters in many cases it is better to 
encode using values below 80h or remapping most of them to looking similar
Latin letters). Encoding given by the directive ENCODE is working until it
is not remapped with the next ENCODE directive. #fromN and #toN can be any
expressions treated as byte values.
 
CTEXT text
text
...
text
ENDTEXT

Special directive to encode text in compact form. Trailing characters
in each line are stored with bit 7 set. Final mark ENDTEXT must be 
starting at the first column in the line.
 
label[:] STRUCT
[label1[:]] {DEFB|DEFW|struct_name} [(#repeat_count)[?]]
...
[labelN[:]] {ESTRUCT|ENDSTRUCT}
Creates number of constants label.label1, label.label2, ... which can be later
used as usual constants in any expression. label1 is set to value 0, and following
labels depending on size of previos fields defined. Also, special function sizeof(label)
become available in expressions for each structure defined. It is also possible 
to use label1, label2 etc. as standalone names.
Note: due to the algorithm used, it is possible to code any instructions or
directives in the structure, but this affects only the offset of the following
labeled fields, and do not generate any bytes in memory.
 
FILE filepath[,start[,length]]
filepath is a path to a binary file to put it into memory (can be enclosed into 
double quotations ("filepath"). Binary file (or length specified) can not exceed 
65536 bytes and it is put as is, byte by byte. Filepath can be also a
list of directories, in such case these are adding to a list of search paths
where the assembler searches for includes.
 
INCLUDE filepath
filepath is a path to a text file to include it as a part of source. filepath
can be enclosed into double quotations ("filepath"). Filepath can be also a
list of directories, in such case these are adding to a list of search paths
where the assembler searches for includes.
 
label[:] MACRO paramlist
  ...
[label2[:]] {ENDM|ENDMACRO|EMAC}
Defines a macro. paramlist can contain: 
- first, a list of fixed parameters
(must be passed in the same order); 
- second, parameters in form name=[default].
For named parameters, these can be passed while calling a macro in any order,
but always in form name=value. Named parameters having default value defined
can be omitted while calling a macro. Formal parameters can be any allowed
identifiers, values passed can be either expressions or strings in single
or double quotations (for case of double quotations, content in quotas is passed
without quotas). MACRO header and ENDM|ENADMACRO|EMAC directives must be the
single statements in the source line. Macro should be defined in the source
before any call to it. Macro definition can be located anywhere in the source
even below places where it is used, and visible always even located in a 
non-processed conditional branch. Do not intersect macro level with other 
preprocessing directive levels. (E.g. mmm MACRO ... IF expr ENDM EIF - is not
correct!)
Any labels defined in the MACRO should be local (otherwise problems possible
using the macro more then once).
About usage of macro parameters, identifiers defined with DEFINE or variable of
the FOR preprocessor loop see below.
 
ERROR [#severity],'text'[,#passes]
or
ERROR [#severity],"text"[,#passes]

Generates a user-defined error. Can be used e.g. in macro to indicate incorrect
parameters passed. severity: 0 - warning (message is displayed but does not affect
compiling; 1 - usual error (code will not be generated more, but the compiler do
not stop immediately); 2 or higher - fatal error, compiler is stopped immediately
displaying a text. If #passes not defined, message is displayed on all compiler 
passes. Otherwise passes is expressed and used as a mask: bit 0 set if to show
at pass 1, bit 1 - at pass 2, and bit2 - at pass3. So, if passes = 2, message
is displayed only at pass 1, if pass = 6 - at pass 2 and 3.
 
DISPLAY 'text'[,#expr[,#passes]]
or
DISPLAY "text"[,#expr[,#passes]]
or
DISPLAY #expr[,#passes]
or
DISPLAY "text",#expr[,"text"[,#expr]]...[,#passes]

Displays a text with #expr value (is present) concatenated (in decimal and hex).
Like for ERROR, #passes (if present) defines a mask of flags indicating for the
compiler on which passes to display a text. It is possible to define several
pairs of text and value to display in a line.
 
label[:] PROC
  ...
[label2[:]] {ENDP|ENDPROC|EPROC}
Defines a procedure. Actually this is used to restrict visibility of labels
defined interior of PROC definition to the other part of source: all such
labels (including label2) become local and known only in the procedure itself.
Procedures can be nested, with no restrictions on nesting level.
 
DUP #expr
  ...
{EDUP|ENDDUP}
Duplicates all the statements defined between DUP and EDUP directives, #expr
times (but if #expr <= 0, all the statements are skipping and do not generate
any code occupying 0 bytes of code, and in such case all the directives there
also do not affect code though it can be checked for correctness).
 
FOR var=values
  ...
{EFOR|ENDFOR}
Duplicates all the statements defined between FOR and EFOR directives for
each listed value, assigning such value to a variable var on each step
like it were made using directive label DEFINE text. A list of values can
contain any expressions, double- or single-quoted strings (while assigning
string double-quoted, only string itself without quotations is assigned),
and also a range in form #from TO #to [STEP #step] is allowed here. FOR
statement must be the last in the line. A list of values can be continued
on the next lines (to continue the list, finish it with the comma at the end).
About usage of macro parameters, identifiers defined with DEFINE or variable of
the FOR preprocessor loop see below.
 
IF #expr [THEN]
  ...
[ELSEIF #expr1 [THEN]
  ...]...
[ELSE 
  ...]
{EIF|ENDIF}
Conditional compiling depending on results of #expr, #expr1, ... calculation.
If any #exprK is not 0, correspondent part of code is compiled and other
parts are skipping.
 
IFcond [THEN]
  ...
[ELSE 
  ...]
{EIF|ENDIF}
cond is one of Z80 conditions (Z,NZ,C,NC,PO,PE,P,M). This is a pseudo-statement 
rather then just a macro. It generates code to jump to ELSE (or EIF, if ELSE is
not defined) branch if cond is not satisfied, and if ELSE is defined, also a jump
is generated to EIF at the end of THEN branch. Short jumps are used if possible.
In case then BREAK or CONTINUE is only a statement in THEN branch, code is 
optimized to use a single jump instruction.
 
LONGIFcond [THEN]
  ...
[LONGELSE 
  ...]
{EIF|ENDIF}
The same as IFcond but always long jumps are used (JP). LONGELSE can be used
with IFcond and LONGIFcond with usual ELSE, and what is used (ELSE or LONGELSE
takes an effect only for jump at the end of the "THEN" branch to the end of
the "ELSE" branch.
 
[label[:]] WHILE
  ...
{EWHILE|EWHILEB|EWHILENZ|EWHILEZ|EWHILENC|EWHILEC|EWHILEPO|EWHILEPE|EWHILEP|EWHILEM}
(in earlier versions it was named LOOP...ELOOP|ELOOPB, if you want you can declare
LOOP DEFINE WHILE
ELOOP DEFINE EWHILE
ELOOPB DEFINE EWHILEB - to provide working of the old code)
Generates a code for infinite loop (EWHILE case), usual DJNZ (ELOOPB case) or for
conditional loop (EWHILEcond).
If DJNZ can not be used (ELOOPB) because of long jump distance, almost equivalent
instructions are used: DEC B:JP NZ,loop (4 bytes long). Anywhere in the loop 
operators BREAK [label] or CONTINUE [label] can be used to leave or continue the loop. 
Using a label in BREAK and CONTINUE statements allows to make a jump outside from 
the nested LOOP.
 
BREAK [label]

See WHILE directive above.
 
CONTINUE [label]

See WHILE directive above.
 
GOTO [cond,][label]

This is an equivalent of JR/JP instruction but the compiler decides if to use
short jump or distance is too far (or condition is not suitable to use short
jump). The important restriction here is that any expression can not be used
as an operand, but only a label, local or global.
 
PUSH rp1[,rp2]...
or
PUSH rp1 [rp2]...

Generates a sequence PUSH rp1:PUSH rp2:... for all the register pair names listed
(AF,BC,DE,HL,IX,IY are allowed as usual).
 
POP rp1[[,]rp2]...
or
POP rp1 [rp2]...

Generates a sequence ...:POP rp2:POP rp1 (register pairs by default are popped in
the inverted order. Use POPNOINVERT and POPINVERT directives to control this order
for such POP directive.
 
POPNOINVERT

See POP directive above.
 
POPINVERT

See POP directive above.
 
END

Finishes code. Any code below this directive will not be compiled.
 

Usage of macro parameters (in macro itself), names defined with DEFINE directive or of the variable of the FOR preprocessor loop.

    Anywhere in visibility area such identifier is replaced with a (string) value assigned to it, i.e. it is substituted for each line with its value (even in a quoted string). Visibility area depends on substituting identifier: for macro parameter it is visible in the macro body when the macro is called, for FOR variable it is visible until EFOR / ENDFOR and for name defined with DEFINE directive - from the definition to the end of the source.
    To allow concatenating the vale with other characters use .name or name. or .name. - while substituting name with its value, neighbor dots will be removed. To code '.' itself use to dots like name..xxxx.
    To allow extracting only a part of value, use following form: "name"[ nnn ] or "name"[ nnn, LLL ] where nnn and LLL are decimal positive numbers. nnn=1 means the first character, LLL can be used to define length of substring extracted (if > 1). Important: character '[' must be the following closing '"' without spaces in between.
    It is also possible to use such values in comparison operations anywhere in the expression in form: "name1" op "name2" or "name1" op string (where op can be one of comparison operation =, <>, <, <=, >, >=). E.g. IF "RP" = DE THEN ...


Alphabetical list of instructions.
ADC HL, { BC | DE | HL | SP }
ADC IX, { BC | DE | IX | SP }
ADC IY, { BC | DE | IY | SP }
ADC [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
ADD HL, { BC | DE | HL | SP }
ADD IX, { BC | DE | IX | SP }
ADD IY, { BC | DE | IY | SP }
ADD [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
AND [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
BIT #number, { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) }
BIT #number, { (IX±#offset ) | (IY±#offset) },
             { B | C | D | E | H | L | A }
CALL [ { NZ | Z | NC | C | PO | PE | P | M }, ] #address
CCF
CP  [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
CPD
CPDR
CPI
CPIR
CPL
DAA
DI
DEC { B | C | D | E | H | L | M | (HL) | A | IXH | IXL | IYH | IYL |
      ( {IX|IY}±#offset ) } 
DI
DJNZ #address
EI
EX (SP), { HL | IX | IY }
EX AF, AF'
EX DE, { HL | IX | IY }
EXX
HALT
IM0 | IM1 | IM2 | IM #n
IN [ A, ] { (#port) | (C) }
IN { B | C | D | E | H | L | F | A }, (C)
INC { B | C | D | E | H | L | M | (HL) | A | IXH | IXL | IYH | IYL |
      ( {IX|IY}±#offset ) } 
IND
INDR
INI
INIR
JP [ { NZ | Z | NC | C | PO | PE | P | M }, ] #address
JR [ { NZ | Z | NC | C }, ] #address
LD A, { I | R | B | C | D | E | H | L | M | (HL ) | A | 
        #expression | IXH | IXL | IYH | IYL | 
       (IX±#offset) | (IY±#offset) | (BC) | (DE) | (#address) }
LD { B | C | D | E | H | L | M | (HL) }, 
   { B | C | D | E | H | L | M | A | #expression }
LD { B | C | D | E | IXH | IXL | A | (IX±#offset) },
   { B | C | D | E | IXH | IXL | A | #expression }
LD { B | C | D | E | IYH | IYL | A | (IY±#offset) },
   { B | C | D | E | IYH | IYL | A | #expression }
LD { B | C | D | E | IXH | IXL | A },
   { B | C | D | E | IXH | IXL | A | (IX±#offset) }
LD { B | C | D | E | IYH | IYL | A },
   { B | C | D | E | IYH | IYL | A | (IY±#offset) }
LD { I | R }, A
LD { BC | DE | HL | SP | IX | IY }, { #expression | ( #address ) }
LD ( #address ), { BC | DE | HL | SP | IX | IY }
LDD
LDDR
LDI
LDIR
NEG
NOP
OR  [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
OUT { (#port) | (C) } [, A ]
OUT (C), { B | C | D | E | H | L | F | A }
OUTD
OTDR
OUTI
OTIR
POP  { BC | DE | HL | AF | IX | IY }
PUSH { BC | DE | HL | AF | IX | IY }
RES #number, { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) }
RES #number, { (IX±#offset ) | (IY±#offset) },
             { B | C | D | E | H | L | A }
RET [ { NZ | Z | NC | C | PO | PE | P | M | N | I } ]
RETI
RETN
RL  { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
RLA
RLC { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
RLCA
RLD
RR  { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
RRA
RRC { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
RRCA
RRD
RST #expression ;
    (allowed following values: 
     0..7 and also 8, 16, 24, 32, 40, 48, 56 - decimal)
SBC HL, { BC | DE | HL | SP }
SBC [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
SCF
SET #number, { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) }
SET #number, { (IX±#offset ) | (IY±#offset) },
             { B | C | D | E | H | L | A }
SLA { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
SLA { (IX±#offset ) | (IY±#offset) },
    { B | C | D | E | H | L | A }
SLI { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
SLI { (IX±#offset ) | (IY±#offset) },
    { B | C | D | E | H | L | A }
SLL { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
SLL { (IX±#offset ) | (IY±#offset) },
    { B | C | D | E | H | L | A }
SRA { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
SRL { B | C | D | E | H | L | M | (HL) | A | 
    IXH | IXL | (IX±#offset ) | (IY±#offset) }
SRL { (IX±#offset ) | (IY±#offset) },
    { B | C | D | E | H | L | A }
SUB [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }
XOR [ A, ] { B | C | D | E | H | L | M | (HL) | A | 
             IXH | IXL | (IX±#offset ) | (IY±#offset) |
             #expression }

Starting from version 2.3 Build 1.5:

Additional rules are added to allow assembling code obtained disassembling a block of memory using Disassemble feature. These are:

- all text following comma ( , ) in brackets is treated as a comment. E.g. LD HL, (0FFFEh,any text here).
- all text following comma in the last operand of the instruction also is treated as a comment. E.g. LD HL,0FFFEh,any text here.
- all numbers having hexadecimal digits are treated as hexadecimal numbers even if those have no leading zero but finishing 'H' char. E.g, FFFFH, 0FFFF, 0FFFFH are allowed, but not FFFF. And, if a label is defined FFFFH, it is overriding FFFFH hexadecimal. So, avoid using labels having only hexadecimal digits and trailing 'H' char.

A feature also added "Set PC" which allow to select from drop down menu (when clicked on a correspondent button on the toolbar in the Assembler window) an address to set to PC in the Debugger.

Left mouse click with Ctrl pressed on a name jumps to a correspondent label in the text (if any such found), adding current position to the history of jumps.

Speed of assembling code is enough fast now to use the Assembler more convenient. In Labels window, use right mouse click to popup a menu with additional options (if to list user and/or system labels e.g.)

Starting from version 2.3 Build 1.5:

- Binary numbers are allowed ( 00010111.B );
- Directive FILE added to include binary files.

New Extensions (version 2.7):

- Colorization of the source text provided.
- Bookmarks in source provided (Ctrl+Shift+n - set bookmark, Ctrl+n - go to bookmark, n - digit key on the keyboard). Bookmarks are saved with the text and restored when loaded.
- Adjusting font size for assembler provided (from Asm options dialog or Ctrl+'+', Ctrl+'-' in the memo).
- Indentations provided (ctrl+shift+I, ctrl+shift+U).
- Smart tabs provided in the editor.
- A lot of changes and improvements in the language itself:

C-- for Z80 embedded.

In C-- statements, all register names are reserved names of predefined variables:
byte A, A', F, F', B, B', C, C', D, D', E, E', H, H', L, L', I, R, IXL, IXH, IYL, IYH
int AF, AF', BC, BC', DE, DE', HL, HL', IX, IY, SP
Also, some accumulator flags are predefined symbols and can be used in some circumstances:
bit CF

Important: a single C-- operator should be written without any internal spaces (but spaces are allowed in the expression or in the parenthesis). C-- operators can be separated from each other or from assembler statements with spaces or symbol ':'. C-- statements as well as most of assembler ones should be written in a single line (division it on parts placed in several neighbor lines is not allowed).

If any register pair is used (and not only in the C-- statement but in any assembler instruction too), it can be auto-incremented or auto-decremented as usual in C, both prefixing or suffixing incrementing and decrementing are allowed. In all such cases the register is incremented or decremented by 1.

Assignment operator: dest=expression. In simple case when dest points to memory but expression is a registry, or otherwise, dest is a registry and expression represents another registry or memory location, and such movement can be compiled to a single direct LD instruction, this is compiled so. E.g.:

A=B LD A,B
A=(HL) LD A,(HL)
A=(IX+10) LD A,(IX+10)
(16384)=SP LD (16384), SP
(DE++)=(HL++) LDI

If an assignment can not be compiled into a direct LD instruction (e.g. moving data from memory to memory), then either register A used as a temporary data storage and is destroying without warning, or stack is used temporarily. E.g.:

(DE)=(BC) LD A,(BC):LD (DE),A
(17000)=(18000) LD A,(18000):LD (17000),A
BC'=BC PUSH BC:EXX:POP BC:EXX
(IX)=DE LD (IX),E:LD (IX+1),D
(HL)=BC LD (HL),C:INC HL:LD (HL),B:DEC HL
(HL++)=BC LD (HL),C:INC HL:LD (HL),B
SP=DE EX DE,HL:LD SP,HL:EX DE,HL
SP=HL' EXX:LD SP,HL:EXX
SP=IY LD SP,IY

Separate operators ++ and -- can be applied only in postfix form and either to a register or register pair or to memory location addressed using HL, IX, IY registers. E.g.:

A++ INC A
HL-- DEC HL
(++HL)-- INC HL:DEC (HL)
(IX+5)++ INC (IX+5)

Other possible operators:
= (assign)
& (and) | (or) ^ (xor)
+ (add) +CF+ (ADC)
- (subtract)  -CF- (SBC)
r<<CF (shift left, RLC) r<< RL r<<- (SLA)
r>>CF (shift right, RRC) r>> RR r>>- (SRA)
>< (swap, exchange instructions)
? (compare)

Possible usage:

A=A+5 ADD A,5
A+B ADD A,B
A-C-CF SBC A,C
&E AND A,E
|(HL) OR A,(HL)
A?(IX+100) CP A,(IX+100)

As you can see, A=A op opd2 can be always replaced with A op opd2 or even op opd2, but at least A' op opd2 must be used if alternative accumulator is used:

A'^E EX AF,AF':XOR A,E:EX AF,AF'

For case of register pairs  (16-bits arithmetics) only prefix Dest= can be omitted in the statement Dest=Dest op Src:

HL=HL+DE ADD HL,DE
HL+BC ADD HL, BC
IX+DE'+CF EXX:ADC IX, DE:EXX
IY+HL EX DE,HL:ADD IY,DE:EX DE,HL

Several samples of shift instructions:

A<< RLA
>>CF RRCA
B<<- SLA B
E'>>- EXX:SRA E:EXX
A'<<CF EX AF,AF':RLCA:EX AF,AF'

Several samples of swap instructions:

HL><DE EX DE,HL
(SP)><DE EX DE,HL:EX (SP),HL:EX DE,HL
IX><BC PUSH IX:PUSH BC:POP IX:POP BC
DE><HL' PUSH DE:EXX:PUSH HL:EXX:POP DE:EXX:POP HL:EXX
AF><AF' EX AF,AF'

 


Last update: 8-Aug-2004

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