HP OpenVMS Systems Documentation

VAX MACRO and Instruction Set Reference Manual

Appendix B
Hexadecimal/Decimal Conversion

The following table lists the decimal value for each possible hexadecimal value in each byte of a longword. The following sections contain instructions to use the table to convert hexadecimal numbers to decimal and decimal numbers to hexadecimal.

B.1 Hexadecimal to Decimal

For each integer position of the hexadecimal value, locate the corresponding column integer and record its decimal equivalent in the conversion table. Add the decimal equivalent to obtain the decimal value.

For example:

D0500AD0 (hex)  =        ?(dec)

D0000000        = 3,489,660,928
  500000        =     5,242,880
     A00        =         2,560
      D0        =           208

D0500AD0        = 3,494,906,576

B.2 Decimal to Hexadecimal

To determine the hexadecimal equivalent of a given decimal value, perform the following steps:

In the conversion table, locate the largest decimal value that does not exceed the decimal number to be converted.
Record the hexadecimal equivalent, followed by the number of zeros that corresponds to the integer column minus 1.
Subtract the table decimal value from the decimal number to be converted.
Repeat steps 1 to 3 until the subtraction balance equals zero. Add the hexadecimal equivalents to obtain the hexadecimal value.

For example:

22,466 (dec)   = ?(hex)

20,480         = 5000        22,466
 1,792         =  700       -20,480
   192         =   C0
     2         =    2         1,986
                            - 1,792
22,466         = 57C2
                                194
                            -   192
                                  2
                            -     2
                                  0

B.3 Powers of 2 and 16

This section lists the decimal values of powers of 2 and 16. These values are useful in converting decimal numbers to hexadecimal.

  Powers of 2               Powers of 16

    2**n     n                  16**n     n

     256     8                      1     0
     512     9                     16     1
    1024    10                    256     2
    2048    11                   4096     3
    4096    12                  65536     4
    8192    13                1048576     5
   16384    14               16777216     6
   32768    15              268435456     7
   65536    16             4294967296     8
  131072    17            68719476736     9
  262144    18          1099511627776    10
  524288    19         17592186044416    11
 1048576    20        281474976710656    12
 2097152    21       4503599627370496    13
 4194304    22      72057594037927936    14
 8388608    23    1152921504606846976    15
16777216    24

Appendix C
VAX MACRO Assembler Directives and Language Summary

This appendix summarizes the general assembler and macro directives (in alphabetical order), special characters, unary operators, binary operators, and addressing modes.

C.1 Assembler Directives

Table C-1 summarizes the VAX MACRO assembler directives.

**Table C-1 Assembler Directives**
Format	Operation
.ADDRESS address-list	Stores successive longwords of address data
.ALIGN keyword[,expression]	Aligns the location counter to the boundary specified by the keyword
.ALIGN integer[,expression]	Aligns location counter to the boundary specified by (2^integer)
.ASCIC string	Stores the ASCII string (enclosed in delimiters), preceded by a count byte
.ASCID string	Stores the ASCII string (enclosed in delimiters), preceded by a string descriptor
.ASCII string	Stores the ASCII string (enclosed in delimiters)
.ASCIZ string	Stores the ASCII string (enclosed in delimiters) followed by a 0 byte
.BLKA expression	Reserves longwords of address data
.BLKB expression	Reserves bytes for data
.BLKD expression	Reserves quadwords for double-precision floating-point data
.BLKF expression	Reserves longwords for single-precision floating-point data
.BLKG expression	Reserves quadwords for floating-point data
.BLKH expression	Reserves octawords for extended-precision floating-point data
.BLKL expression	Reserves longwords for data
.BLKO expression	Reserves octawords for data
.BLKQ expression	Reserves quadwords for data
.BLKW expression	Reserves words for data
.BYTE expression-list	Generates successive bytes of data; each byte contains the value of the specified expression
.CROSS	Enables cross-referencing of all symbols
.CROSS symbol-list	Cross-references specified symbols
.DEBUG symbol-list	Makes symbol names known to the debugger
.DEFAULT DISPLACEMENT, keyword	Specifies the default displacement length for the relative addressing modes
.D_FLOATING literal-list	Generates 8-byte double-precision floating-point data
.DISABLE argument-list	Disables functions specified in argument-list
.DOUBLE literal-list	Equivalent to .D_FLOATING
.DSABL argument-list	Equivalent to .DISABLE
.ENABL argument-list	Equivalent to .ENABLE
.ENABLE argument-list	Enables functions specified in argument-list
.END [symbol]	Indicates logical end of source program; optional symbol specifies transfer address
.ENDC	Indicates end of conditional assembly block
.ENDM [macro-name]	Indicates end of macro definition
.ENDR	Indicates end of repeat block
.ENTRY symbol [,expression]	Procedure entry directive
.ERROR [expression] ;comment	Displays specified error message
.EVEN	Ensures that the current location counter has an even value (adds 1 if it is odd)
.EXTERNAL symbol-list	Indicates specified symbols are externally defined
.EXTRN symbol-list	Equivalent to .EXTERNAL
.F_FLOATING literal-list	Generates 4-byte single-precision floating-point data
.FLOAT literal-list	Equivalent to .F_FLOATING
.G_FLOATING literal-list	Generates 8-byte G_floating-point data
.GLOBAL symbol-list	Indicates specified symbols are global symbols
.GLOBL	Equivalent to .GLOBAL
.H_FLOATING literal-list	Generates 16-byte extended-precision H_floating-point data
.IDENT string	Provides means of labeling object module with additional data
.IF condition [,] argument(s)	Begins a conditional assembly block of source code, which is included in the assembly only if the stated condition is met with respect to the arguments specified
.IFF	Equivalent to .IF_FALSE
.IF_FALSE	Appears only within a conditional assembly block; begins block of code to be assembled if the original condition tests false
.IFT	Equivalent to .IF_TRUE
.IFTF	Equivalent to .IF_TRUE_FALSE
.IF_TRUE	Appears only within a conditional assembly block; begins block of code to be assembled if the original condition tests true
.IF_TRUE_FALSE	Appears only within a conditional assembly block; begins block of code to be assembled unconditionally
.IIF condition argument(s), statement	Acts as a 1-line conditional assembly block where the condition is tested for the argument specified; the statement is assembled only if the condition tests true
.IRP symbol,<argument list>	Replaces a formal argument with successive actual arguments specified in an argument list
.IRPC symbol,<BIT_STRING>	Replaces a formal argument with successive single characters specified in string
.LIBRARY macro-library-name	Specifies a macro library
.LINK "file-spec" [/qualifier[=(module-name[,...])],...]	Includes linker option records in object module
.LIST [argument-list]	Equivalent to .SHOW
.LONG expression-list	Generates successive longwords of data; each longword contains the value of the specified expression
.MACRO macro-name [formal-argument-list]	Begins a macro definition
.MASK symbol [,expression]	Reserves a word for and copies a register save mask
.MCALL macro-name-list	Specifies the system or user-defined macros, or both, in libraries that are required to assemble the source program
.MDELETE macro-name-list	Deletes from memory the macro definitions of the macros in the list
.MEXIT	Exits from the expansion of a macro before the end of the macro is encountered
.NARG symbol	Determines the number of arguments in the current macro call
.NCHR symbol,<BIT_STRING>	Determines the number of characters in a specified character string
.NLIST [argument-list]	Equivalent to .NOSHOW
.NOCROSS	Disables cross-referencing of all symbols
.NOCROSS symbol-list	Disables cross-referencing of specified symbols
.NOSHOW	Decrements listing level count
.NOSHOW argument-list	Controls listing of macros and conditional assembly blocks
.NTYPE symbol,operand	Can appear only within a macro definition; equates the symbol to the addressing mode of the specified operand
.OCTA literal	Stores 16 bytes of data
.OCTA symbol	Stores 16 bytes of data
.ODD	Ensures that the current location counter has an odd value (adds 1 if it is even)
.OPDEF opcode value, operand-descriptor-list	Defines an opcode and its operand list
.PACKED decimal-string [,symbol]	Generates packed decimal data, 2 digits per byte
.PAGE	Causes the assembly listing to skip to the top of the next page and to increment the page count
.PRINT [expression] ;comment	Displays the specified message
.PSECT	Begins or resumes the blank program section
.PSECT section-name argument list	Begins or resumes a user-defined program section
.QUAD literal	Stores 8 bytes of data
.QUAD symbol	Stores 8 bytes of data
.REF1 operand	Generates byte operand
.REF2 operand	Generates word operand
.REF4 operand	Generates longword operand
.REF8 operand	Generates quadword operand
.REF16 operand	Generates octaword operand
.REPEAT expression	Begins a repeat block; the section of code up to the next .ENDR directive is repeated the number of times specified by the expression
.REPT	Equivalent to .REPEAT
.RESTORE	Equivalent to .RESTORE_PSECT
.RESTORE_PSECT	Restores program section context from the program section context stack
.SAVE [LOCAL_BLOCK]	Equivalent to .SAVE_PSECT
.SAVE_PSECT [LOCAL_BLOCK]	Saves current program section context on the program section context stack
.SBTTL comment-string	Equivalent to .SUBTITLE
.SHOW	Increments listing level count
.SHOW argument-list	Controls listing of macros and conditional assembly blocks
.SIGNED_BYTE expression-list	Stores successive bytes of signed data
.SIGNED_WORD expression-list	Stores successive words of signed data
.SUBTITLE comment-string	Causes the specified string to be printed as part of the assembly listing page header; the string component of each .SUBTITLE is collected into a table of contents at the beginning of the assembly listing
.TITLE module-name comment-string	Assigns the first 15 characters in the string as an object module name and causes the string to appear on each page of the assembly listing
.TRANSFER symbol	Directs the linker to redefine the value of the global symbol for use in a shareable image
.WARN [expression] ;comment	Displays specified warning message
.WEAK symbol-list	Indicates that each of the listed symbols has the weak attribute
.WORD expression-list	Generates successive words of data; each word contains the value of the corresponding specified expression

C.2 Special Characters

Table C-2 summarizes the VAX MACRO special characters.

**Table C-2 Special Characters Used in VAX MACRO Statements**
Character	Character Name	Functions
_	Underscore	Character in symbol names
$	Dollar sign	Character in symbol names
.	Period	Character in symbol names, current location counter, and decimal point
:	Colon	Label terminator
=	Equal sign	Direct assignment operator and macro keyword argument terminator
	Tab	Field terminator
	Space	Field terminator
#	Number sign	Immediate addressing mode indicator
@	At sign	Deferred addressing mode indicator and arithmetic shift operator
,	Comma	Field, operand, and item separator
;	Semicolon	Comment field indicator
+	Plus sign	Autoincrement addressing mode indicator, unary plus operator, and arithmetic addition operator
-	Minus sign	Autodecrement addressing mode indicator, unary minus operator, arithmetic subtraction operator, and line continuation indicator
*	Asterisk	Arithmetic multiplication operator
/	Slash	Arithmetic division operator
&	Ampersand	Logical AND operator
!	Exclamation point	Logical inclusive OR operator
\	Backslash	Logical exclusive OR and numeric conversion indicator in macro arguments
^	Circumflex	Unary operator indicator and macro argument delimiter
[ ]	Square brackets	Index addressing mode and repeat count indicators
( )	Parentheses	Register deferred addressing mode indicators
<>	Angle brackets	Argument or expression grouping delimiters
?	Question mark	Created label indicator in macro arguments
'	Apostrophe	Macro argument concatenation indicator
%	Percent sign	Macro string operators

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