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Text File | 1985-08-11 | 11.8 KB | 461 lines | [TEXT/Anon]

MAC.68K LOCAL LOCAL LOCAL PURPOSE To define unique names for use within a macro definition. FORMAT LOCAL symbol1,symbol2,...symbolN DESCRIPTION LOCAL must immediately follow the MACRO or MACROL pseudo op. It contains a list of symbols that are to be used only within the macro body. During macro expansion, local symbols are replaced with a symbol name of ..hhhh where hhhh is a hex number starting at 0000 and being incremented by one each time a local symbol is generated. By generating unique names for each macro call, a macro may use internal location symbols or EQUs and not produce duplicate name errors if called more than once. Local symbols do not appear in the symbol table and are not cross referenced. EXAMPLE ZEROUT MACRO LOCATION,COUNT LOCAL LOOP,EXIT MOVE #COUNT,D0 BLE.S EXIT LEA LOCATION,A0 LOOP CLR.B (A0)+ DBF D0,LOOP EXIT DS 0 ENDM -45- MAC.68K MAC.68K MACRO MACRO MACRO PURPOSE To define a macro. FORMAT macroname MACRO parameter1,parameter2,...parameterN DESCRIPTION MACRO is followed by a block of code terminated by an ENDM. This block of code, called the macro body, is saved and may be inserted into the program assembly at any future point by using the macro name as an operation code. A macro may be defined with 0 to 127 formal parameters. The parameters are listed in the operand field of the MACRO statement and are separated by commas. A parameter may be any valid symbol name. These parameters may appear in any instruction field within the body of the macro. At macro call time, when the macro name is used as an operation code, the operand field contains its own list of actual parameters separated by commas. The first actual parameter is substituted for all occurances of the first formal parameter in the macro body, the second actual parameter is substituted for all appearances of the second formal parameter, and so on. The resulting block of code, called the macro expansion, is inserted into the assembly immediately following the macro call. Local symbols and macro parameters are recognized in the macro body if they are delimited by: space + - * / ( ) & , = " Any actual macro parameter may be placed in parenthesis. This is especially useful for passing special characters such as commas or spaces. An actual parameter may be null. Its macro body substitution will also be null. A symbol in the location field of a MACRO call is assigned a permanent value equal to the location counter prior to the macro expansion. Macro expansions may contain calls to other macros or even to the same macro. A limit of 5 nested macro calls is allowed. MAC.68K -46- MAC.68K EXAMPLES definition call expansion TEST MACRO TEST null ENDM ADD3 MACRO P1,P2,P3 ADD3 7,8,9 MOVE 7,D1 MOVE P1,D1 ADD 8,D1 ADD P2,D1 ADD 9,D1 ADD P3,D1 ENDM CADD MACRO P1,P2,P3 CADD 4,5 MOVE 4,D1 LOCAL JTAG IFS NE,*5**,1 MOVE P1,D1 ADD 5,D1 IFS NE,*P2**,1 IFS EQ,*** ADD P2,D1 BRA.S ..0000 IFS EQ,*P3** OR $FFFE,D1 BRA.S JTAG ..0000 DS 0 ELSE ADD P3,D1 CADD 4,,6 MOVE 4,D1 ENDC IFS NE,***,1 OR #$FFFE,D1 IFS EQ,*6** JTAG DS 0 ELSE ENDM ADD 6,D1 OR #$FFFFE,D0 ..0001 DS 0 MACROL MACROL MACROL PURPOSE To define a macro. FORMAT macroname MACROL parameter1,parameter2,...parameterN DESCRIPTION MACROL is similiar to macro except that on the MACROL call the location field is treated as call parameter 1 instead of as a location field symbol. (See example for STRLEN) -47- MAC.68K MAC.68K MAX MAX MAX PURPOSE To generate a redefinable symbol equal to the largest value from the expression list in the operand field. FORMAT symbol MAX expression1,expression2,...expressionN DESCRIPTION MAX evaluates the expressions in the operand list and assigns the largest value found to the redefinable symbol in the location field. All symbols used in the expressions must be previously defined. If any errors are encountered the symbol is not (re)defined. MIN MIN MIN PURPOSE To generate a redefinable symbol equal to the smallest value from the expression list in the operand field. FORMAT symbol MIN expression1,expression2,...expressionN DESCRIPTION MIN evaluates the expressions in the operand list and assigns the smallest value found to the redefinable symbol in the location field. All symbols used in the expressions must be previously defined. If any errors are encountered the symbol is not (re)defined. EXAMPLES FOO MAX PAGESIZE,80 BAZ MIN LENGTH1,LENGTH2,LENGTH3 MAC.68K -48- MAC.68K MODULE MODULE MODULE PURPOSE To indicate a MAC.68K module assembly. The object file is generated with a .MOD file extension. FORMAT MODULE DESCRIPTION MODULE is an initialization directive. It must appear after the IDENT card but before any noninitialization operation codes. MODULE generates the .MOD files used with INCLUDEH. A module may contain CPU instructions and/or data. It differs from an included text file in that the module is assembled prior to its use and is converted from text into actual machine code. The default origin address for a module is $0 and there is no associated load address. Because it may be called anywhere within another program, a module should use relative addressing and avoid absolute addressing. A module may not use DATA or BSS segments. -49- MAC.68K MAC.68K NOREF NOREF NOREF PURPOSE To disable cross references for specified symbols. FORMAT NOREF symbol1,symbol2,...symbolN DESCRIPTION NOREF turns off cross referencing for the specified symbols. Symbols in the NOREF list must be already defined. EXAMPLE NOREF TAG,TAG1 OFFSET OFFSET OFFSET PURPOSE To change the assembly to an offset segment. FORMAT OFFSET expression DESCRIPTION OFFSET switches the assembly to a null segment. It is useful for defining symbols with values relative (offset) to the start of a table or buffer. Any type of instruction, data, or reservation op code may be used. Only the symbols in an offset segment are retained, any code, data, or reservation locations do not appear in the object file. The default starting offset address is zero. If expression is used, the value of the expression becomes the starting address for this offset segment. An offset segment, like any other segment, is terminated when the assembly is switched to another segment with a BSS, DATA, TEXT, SECTION, or END card. MAC.68K -50- MAC.68K OPSYN OPSYN OPSYN PURPOSE To equate a new operation code to an existing operation code, pseudo operation code, or macro name. FORMAT newname OPSYN opname DESCRIPTION OPSYN equates a new operation code, newname , to an existing operation name. This new name is independent of the existing name and is not affected by any later redefinition or PURGE of the existing name. EXAMPLE REPT OPSYN DUP EJECT OPSYN PAGE -51- MAC.68K -51-