14.1.2 Directives

CEF directives typically start with a period (“.”). Exceptions are described in the following text. The standard CEF directives are:

.ADDRESS directive

Format: .ADDRESS n

Defines data the size of the virtual address space. For instance, if the CPU maximum virtual address is FFFF (hex), this will define two bytes containing value "n".

.ALIGN directive

Format; .ALIGN {n}

Synonym: ALIGN

Align to next n bytes. n can be either a number or one of the following values:

BYTE

WORD

LONG

QUAD

OCTA

PARAGRAPH

PAGE

If a numeric value is specified, the byte alignment is equal to 2^n bytes. For instance, "ALIGN 2" would align to a 4 byte boundary. PARAGRAPH and OCTA are equivalent. PAGE depends on the CPU page size. If "n" is omitted, the directive is equivalent to "ALIGN PAGE".

.ASCIC directive

Format: .ASCIC s

ASCII data with length prefix byte. "s" is a string literal. See the .ASCII directive for details on its format.

.ASCII directive

Format: .ASCII s

ASCII data. "s" is a string literal. This literal must be delimited by a non-space character. The delimiter is whichever non-space character immediately follows the directive. The delimiter must occur at the end of the string as well. Multiple strings can follow so long as each is delimited. Non-printable characters can be included by placing the value of the character within angle brackets (<>) outside of the quote characters. Any expression can be placed within the angle brackets, which will be evaluated and the character corresponding to that ASCII value will be substituted. Note that any space or tab occuring outside of quote characters will terminate the text specification. Examples:

.ASCII "This is text"

.ASCII /Some more text/

.ASCII /New line: /<13.><10.> ; CRLF

.ASCII 'This ''is ''also ''text'

.ASCIZ directive

Format: .ASCIZ s

ASCII data with terminating null byte. "s" is a string literal. See the .ASCII directive for details on its format.

.BCD directive

Format: .BCD n

Defines a Binary-coded Decimal formatted value of value n. Example:

.BCD 8228

.BLKA directive

Format: .BLKA n

Reserves n * x bytes of uninitialized data where "x" is the size of the virtual address space. For instance, assume that the CPU has a maximum virtual address of FFFF (hex). Thus, ".BLKA 3" would reserve 6 bytes.

.BLKB directive

Format: .BLKB n

Synonyms: DS n

.BLOCK n

.DS n

DEFS n

.DEFS n

Reserves n bytes of uninitialized data.

.BLKD directive

Format: .BLKD n

Reserves n * 8 bytes of uninitialized (double-precision floating-point) data.

.BLKF directive

Format: .BLKF n

Reserves n * 4 bytes of uninitialized (floating-point) data.

.BLKL directive

Format: .BLKL n

Reserves n * 4 bytes of uninitialized (long) data.

.BLKO directive

Format: .BLKO n

Reserves n * 16 bytes of uninitialized (octa) data.

.BLKQ directive

Format: .BLKQ n

Reserves n * 8 bytes of uninitialized (quad) data.

.BLKW directive

Format: .BLKW n

Reserved n * 2 bytes of uninitialized data.

.CODES directive

Format: .CODES

See also: .NOCODES

Earliest Version: 2.1

Turns on the display of generated data in the listing output. This is the default.

.DB directive

Format: .DB n{,n...}

Synonyms: DB n

DEFB n

.DEFB n

.BYTE n

.SIGNED_BYTE n

Format: .DB "n"

Synonyms: DB "n"

Reserves byte(s) of data. DB and .DB can be followed by a quoted text or an expression. The expression can include quoted characters. See the section on expressions for more details. A comma-delimited list of values may follow. Examples:

.DB '#'

.DB '0' - 32

.BYTE 4,'Text',TTY/2

.DEFINE directive

Format: .DEFINE s

Defines a conditional symbol. "s" is the symbol name. Example:

.DEFINE Test_Mode

#DEFINE directive

Format: #DEFINE name{arguments} definition

Defines a single-line macro. See the section on macros for more information.

.DEFM directive

Format: .DEFM "s"

Synonyms: DEFM "s"

(see also .TEXT)

Stores ASCII data. The ASCII data must be delimited by double quotes (") or single quotes ('). Multiple delimited strings may appear after the directive. Examples:

.DEFM 'This is ASCII text'

.DEFM 'He said, "It'"'s too bad"'"'

The second example stores the following:

He said, "It's too bad"

.DOUBLE directive

Format: .DOUBLE n

Synonyms: .D_FLOATING n

Defines Double-precision floating point data (8 bytes). "n" is a floating-point numeric value. Examples:

.DOUBLE 3.14159

.DWORD directive

Format: .DWORD n

Synonyms: DD n

.DD n

DEFD n

.DEFD n

Stores "n" as a 4 byte value. Example:

.DWORD 32767.

.EJECT directive

Format: .EJECT

Earliest spec: 2.1

This moves the assembly listing to the top of the next page.

.ELSE directive

Format: .ELSE

This is used in conditional assembly. It is only valid within IF block. See the section on conditional assembly for details.

.END directive

Format: .END {a}

Synonyms: END {a}

End of assembly source. The assembler does not process any text past this directive. The optional address defines where code execution will begin.

.ENDC directive

Format: .ENDC

End conditional. Terminates an IF block. See the section on conditional assembly for details..

#ENDIF

Format; #ENDIF

Ends a #IF block.

.ENDM directive

Format: .ENDM

Ends a macro. See the section on macros for details.

.ENDR directive

Format: .ENDR

Ends a repeat block started by .REPEAT, .IRP, or .IRPC.

.EOT directive

Format: .EOT

Null directive. Has no effect.

EQU directive

Format: s EQU v

Synonym: s = v

Equate symbol s to value v. Example:

Space EQU 32

Exclamation = 33

.ERROR directive

Format: .ERROR {s;}m

Generates an assembly-time error with text "m". An optional expression "s" is evaluated and shown as well.

.EVEN directive

Format: .EVEN

Synonyms: .ALIGN 1

Adjusts to an even address. If on an odd address, a byte of 0 is inserted.

.IIF directive

Format: .IIF condition {,}arguments, statement

Immediate conditional assembly. The condition and argument(s) must be separated by a space, tab, or comma. The arguments depend upon the condition. See the section on conditional assembly for details on conditions. If the condition is true, the statement will be assembled.

Example:

.IIF DEFINED Test_Mode, .DEFM "Testing"

.IF directive

Format: .IF condition arguments

See also: #IF

Begins conditional assembly. See the section on conditional assembly for details.

.IF_ directives

.IF_TRUE conditional assembly. .IFT

.IF_FALSE conditional assembly. .IFF

.IF_TRUE_FALSE conditional assembly. .IFTF

Used to switch within an IF block. See the section on conditional assembly for details.

#IF directive

Format: #IF(condition)

See also: .IF

Begins conditional assembly. This differs from the .IF directive. The IF block is terminated with #ENDIF. The condition has the format: expression1 operator expression2

where “expression 1” and “expression 2” are simple expressions and “operator” is one of the following conditional operators:

Examples:

#if(P1 < P2)

.DB 1

#endif

#if((P1-1) != (P2 * 2))

.DB FFH

#endif

.INCLUDE directive

Format: .INCLUDE x

Synonyms: INCLUDE x

Includes another file at the current position. "x" is the name of the file to include. The entire remainder of the line after the directive is considered to be the file name.

.IRP directive

Format: .IRP symbol, arguments

Indefinite repeat. "symbol" is a symbol that is replaced with successive arguments within the repeat block, which is ended by the .ENDR directive. "arguments" is one or more areguments separeted by commas. The argument list is delimited by angle brackets (<>) or matched delimiters. Matched delimiters are indicated by using a circumflex (^) followed by the delimiter. Examples:

.IRP ARG,<32,33>

.BYTE ARG

.ENDR

.IRP ARG,^X0,64,127,129X

.BYTE ARG

.ENDR

.IRPC directive

Format: .IRPC symbol,string

Indefinite repeats characters in "string". "symbol" is a symbol that is replaced with successive chraracters within the repeat block, which is ended by the .ENDR directive. The string may be delimited as defined in the .IRP directive description. However, it is not required that the string be delimited. Examples:

.IRPC ARG,SYMBOL

.DB 'ARG'

.ENDR

.IRPC ARG,<TopsyTurvey>

.DB 'ARG'

.EDNR

.LSFIRST directive

Format: .LSFIRST

See also: .MSFIRST

Earliest version: 2.1

Sets data to little-endian (least significant data in lower addresses).

.MACRO directive

Format: .MACRO name

Begins a macro definition. See the section on macros for details.

.MDELETE directive

Format: .MDELETE x

Deletes the macro named "x". This can be used within the named macro to allow it to execute only once.

.MEXIT directive

Format: .MEXIT

Exit a macro expansion before the .ENDM.

.MSFIRST directive

Format: .MSFIRST

See also: .LSFIRST

Earliest version: 2.1

Sets data to big-endian (most significant data in lower addresses).

.NARG directive

Format: .NARG s

Determine number of macro arguments. The number of arguments passed

to the current macro is assigned to symbol "s". This is only valid

within a macro block. See the section on macros for more details.

.NCHR directive

Format: .NCHR symbol, string

Counts the number of characters in "string" and assigns that value to symbol "symbol". The primary purpose is for determining the length of macro arguments. "string" does not have to be delimited unless it starts with "<" or "^". It can be delimited between "<" and ">", or with any other character if that character is preceded with a circumflex (^). Examples:

.NCHR COUNT, ARG

.NCHR COUNT, <How many?>

.NCHR C, ^XHow many?X

.NOCODES directive

Format: .NOCODES

See also: .CODES

Earliest Version: 2.1

Turns off the display of generated data in the listing output. This is the default.

.NOPAGE directive

Format: .NOPAGE

See also: .PAGE

Earliest version: 2.1

Turns paging off in assembler listing output.

.ODD directive

Format: .ODD

Align to odd byte address.

.ORG directive

Format: .ORG a

Synonym: ORG a

Position the current instruction position to address "a". Also sets the destination address of subsequent assembled code.

.PACKED directive

Format: .PACKED n

Store a packed BCD value for n. Example:

.PACKED 123.45

.PAGE directive

Format: .PAGE

See also: .NOPAGE

Earliest version: 2.1

Turns paging on in assembler listing output. When on, the listing provides a three-line header and a three-line footer on each page of 66 lines. A form feed (ASCII 12) is used to move to the top of the next page when .EJECT is encountered or the page fills.

.RADIX directive

Format: .RADIX n

Use base n for numeric literals. n must be in the range 2<=n<=36

.RADIX50 directive

Format: .RADIX50 s

Store radix-50 data for the string "s". Multiple strings, delimited by commas, may be specified. Example:

.RADIX50

.REF directives

Format: .REF1 n

Synonym: .BYTE n

Store 1 byte of data of value n. n must be an integer value.

Format: .REF2 n

Synonym: .WORD n

Store 2 bytes of data of value n. n must be an integer value.

Format: .REF4 n

Synonym: .LONG n

Store 4 bytes of data of value n. n must be an integer value.

Format: .REF8 n

Synonym: .QUAD n

Store 8 bytes of data of value n. n must be an integer value.

Format: .REF16 n

Synonym: .OCTA n

Store 16 bytes of data of value n. n must be an integer value.

.REMARK directive

Format: .REM{ARK}

Synonym: COMMENT

Source comment line. The entire line after the directive is ignored as a comment.

.REPEAT directive

Format: .REPEAT n

Synonym: .REPT n

Repeat a block n times, where n is an integer. The block is terminated with .ENDR.

.SET_TARGET_CPU

Format: .SET_TARGET_CPU name

Set the target CPU for assembly to the CPU with the specified name. This name is the name of the component loaded via the LOAD command in an emulator command file.

.SINGLE directive

Format: .SINGLE n

Synonyms: .FLOAT n

.S_FLOATING n

Stores a single-precision (4 byte) floating-point value. Example:

.FLOAT 2.46E+10

.TEXT directive

Format: .TEXT "s"

Earliest spec: 2.1

See also .DEFM

Stores ASCII data. The data must be delimited by double quotes (") or single quotes ('). Multiple delimited strings may appear after the directive. Escape codes are allowed in the text. An escape code begins with a backslash (\). Valid escape codes:

Examples:

.TEXT 'This is ASCII text'”More text'

.TEXT '>\t Press Enter to continue\r\n\000'

.TITLE directive

Format: .TITLE x

Earliest spec: 2.1

Sets the Assembly listing page title to “x”.

.UNDEFINE directive

Format: .UNDEFINE s

Undefines symbol "s". The symbol is removed from the symbol table.

.WARN directive

Format: .WARN {s,}m

Synonym: .WARNING {s,}m

Generates an assembly-time warning with text "m". An optional expression "s" is evaluated and shown as well.

.WORD directive

Format: .WORD n

Synonyms: DW n

.DW n

DEFW n

.DEFW n

.SIGNED_WORD n

Stores 2 bytes of data of value n, where n is an integer.