ASxxxx Assemblers and ASLINK Relocating Linker CHAPTER 1 THE ASSEMBLER 1-1 1.1 THE ASXXXX ASSEMBLERS 1-1 1.1.1 Assembly Pass 1 1-2 1.1.2 Assembly Pass 2 1-2 1.1.3 Assembly Pass 3 1-2 1.2 SOURCE PROGRAM FORMAT 1-3 1.2.1 Statement Format 1-3 1.2.1.1 Label Field 1-3 1.2.1.2 Operator Field 1-5 1.2.1.3 Operand Field 1-5 1.2.1.4 Comment Field 1-6 1.3 SYMBOLS AND EXPRESSIONS 1-6 1.3.1 Character Set 1-6 1.3.2 User-Defined Symbols 1-10 1.3.3 Local Symbols 1-11 1.3.4 Current Location Counter 1-12 1.3.5 Numbers 1-14 1.3.6 Terms 1-14 1.3.7 Expressions 1-15 1.4 GENERAL ASSEMBLER DIRECTIVES 1-16 1.4.1 .module Directive 1-16 1.4.2 .title Directive 1-17 1.4.3 .sbttl Directive 1-17 1.4.4 .page Directive 1-17 1.4.5 .byte and .db Directives 1-17 1.4.6 .word and .dw Directives 1-18 1.4.7 .blkb, .blkw, and .ds Directives 1-18 1.4.8 .ascii Directive 1-18 1.4.9 .asciz Directive 1-19 1.4.10 .radix Directive 1-19 1.4.11 .even Directive 1-20 1.4.12 .odd Directive 1-20 1.4.13 .area Directive 1-20 1.4.14 .org Directive 1-21 1.4.15 .globl Directive 1-22 1.4.16 .if, .else, and .endif Directives 1-22 1.4.17 .include Directive 1-23 1.5 INVOKING ASXXXX 1-24 1.6 ERRORS 1-25 1.7 LISTING FILE 1-26 1.8 SYMBOL TABLE FILE 1-27 1.9 OBJECT FILE 1-28 CHAPTER 2 THE LINKER 2-1 2.1 ASLINK RELOCATING LINKER 2-1 2.2 INVOKING ASLINK 2-2 2.3 ASLINK PROCESSING 2-3 2.4 LINKER INPUT FORMAT 2-4 2.4.1 Object Module Format 2-4 2.4.2 Header Line 2-5 2.4.3 Module Line 2-5 2.4.4 Symbol Line 2-5 2.4.5 Area Line 2-5 2.4.6 T Line 2-6 2.4.7 R Line 2-6 CHAPTER 3 BUILDING ASXXXX AND ASLINK 3-1 3.1 BUILDING AN ASSEMBLER 3-1 Page ii 3.2 BUILDING ASLINK 3-2 APPENDIX A AS6800 ASSEMBLER A-1 A.1 .setdp DIRECTIVE A-1 A.2 6800 REGISTER SET A-1 A.3 6800 INSTRUCTION SET A-2 A.3.1 Inherent Instructions A-3 A.3.2 Branch Instructions A-3 A.3.3 Single Operand Instructions A-4 A.3.4 Double Operand Instructions A-5 A.3.5 Jump and Jump to Subroutine Instructions A-5 A.3.6 Long Register Instructions A-6 APPENDIX B AS6801 ASSEMBLER B-1 B.1 .setdp DIRECTIVE B-1 B.2 .hd6303 DIRECTIVE B-1 B.3 6801 REGISTER SET B-2 B.4 6801 INSTRUCTION SET B-2 B.4.1 Inherent Instructions B-3 B.4.2 Branch Instructions B-3 B.4.3 Single Operand Instructions B-3 B.4.4 Double Operand Instructions B-5 B.4.5 Jump and Jump to Subroutine Instructions B-5 B.4.6 Long Register Instructions B-5 B.4.7 6303 Specific Instructions B-6 APPENDIX C AS6804 ASSEMBLER C-1 C.1 6804 REGISTER SET C-1 C.2 6804 INSTRUCTION SET C-1 C.2.1 Inherent Instructions C-2 C.2.2 Branch Instructions C-2 C.2.3 Single Operand Instructions C-2 C.2.4 Jump and Jump to Subroutine Instructions C-2 C.2.5 Bit Test Instructions C-2 C.2.6 Load Immediate data Instruction C-3 C.2.7 6804 Derived Instructions C-3 APPENDIX D AS6805 ASSEMBLER D-1 D.1 .setdp DIRECTIVE D-1 D.2 6805 REGISTER SET D-1 D.3 6805 INSTRUCTION SET D-2 D.3.1 Control Instructions D-2 D.3.2 Bit Manipulation Instructions D-3 D.3.3 Branch Instructions D-3 D.3.4 Read-Modify-Write Instructions D-4 D.3.5 Register\Memory Instructions D-4 D.3.6 Jump and Jump to Subroutine Instructions D-5 APPENDIX E AS6809 ASSEMBLER E-1 E.1 .setdp DIRECTIVE E-1 E.2 6809 REGISTER SET E-1 E.3 6809 INSTRUCTION SET E-2 E.3.1 Inherent Instructions E-4 E.3.2 Short Branch Instructions E-4 Page iii E.3.3 Long Branch Instructions E-4 E.3.4 Single Operand Instructions E-5 E.3.5 Double Operand Instructions E-6 E.3.6 D-register Instructions E-6 E.3.7 Index/Stack Register Instructions E-6 E.3.8 Jump and Jump to Subroutine Instructions E-7 E.3.9 Register - Register Instructions E-7 E.3.10 Condition Code Register Instructions E-7 E.3.11 6800 Compatibility Instructions E-7 APPENDIX F AS6811 ASSEMBLER F-1 F.1 .setdp DIRECTIVE F-1 F.2 6811 REGISTER SET F-1 F.3 6811 INSTRUCTION SET F-2 F.3.1 Inherent Instructions F-3 F.3.2 Branch Instructions F-3 F.3.3 Single Operand Instructions F-4 F.3.4 Double Operand Instructions F-5 F.3.5 Bit Manupulation Instructions F-5 F.3.6 Jump and Jump to Subroutine Instructions F-6 F.3.7 Long Register Instructions F-6 APPENDIX G AS8085 ASSEMBLER G-1 G.1 8085 REGISTER SET G-1 G.2 8085 INSTRUCTION SET G-1 G.2.1 Inherent Instructions G-2 G.2.2 Register/Memory/Immediate Instructions G-2 G.2.3 Call and Return Instructions G-2 G.2.4 Jump Instructions G-2 G.2.5 Input/Output/Reset Instructions G-3 G.2.6 Move Instructions G-3 G.2.7 Other Instructions G-3 APPENDIX H ASZ80 ASSEMBLER H-1 H.1 .hd64 DIRECTIVE H-1 H.2 Z80 REGISTER SET AND CONDITIONS H-1 H.3 Z80 INSTRUCTION SET H-2 H.3.1 Inherent Instructions H-3 H.3.2 Implicit Operand Instructions H-3 H.3.3 Load Instruction H-4 H.3.4 Call/Return Instructions H-4 H.3.5 Jump and Jump to Subroutine Instructions H-4 H.3.6 Bit Manipulation Instructions H-5 H.3.7 Interrupt Mode and Reset Instructions H-5 H.3.8 Input and Output Instructions H-5 H.3.9 Register Pair Instructions H-5 H.3.10 HD64180 Specific Instructions H-6 Page iv P R E F A C E The ASxxxx assemblers were written following the style of several cross assemblers found in the Digital Equipment Corpora- tion Users Society (DECUS) distribution of the C programming language. The DECUS code was provided with no documentation as to the input syntax or the output format. Study of the code revealed that the unknown author of the code had attempted to formulate an assembler with attributes similiar to those of the PDP-11 MACRO assembler (without macro's). The incomplete code from the DECUS C distribution has been largely rewritten, only the program structure, and C source file organization remains relatively unchanged. However, I wish to thank the author for his contribution to this set of assemblers. The ASLINK program was written as a companion to the ASxxxx assemblers, its design and implementation was not derived from any other work. The ASxxxx assemblers and the ASLINK relocating linker are placed in the Public Domain. Publication or distribution of these programs for non-commercial use is hereby granted with the stipulation that the copyright notice be included with all copies. I would greatly appreciate receiving the details of any changes, additions, or errors pertaining to these programs and will attempt to incorporate any fixes or generally useful changes in a future update to these programs. Alan R. Baldwin Kent State University Physics Department Kent, Ohio 44242 CHAPTER 1 THE ASSEMBLER 1.1 THE ASXXXX ASSEMBLERS The ASxxxx assemblers are a series of microprocessor assem- blers written in the C programming language. Each assembler has a device specific section which includes: 1. device description, byte order, and file extension in- formation 2. a table of the assembler general directives, special device directives, assembler mnemonics and associated operation codes 3. machine specific code for processing the device mnemon- ics, addressing modes, and special directives The device specific information is detailed in the appendices. The assemblers have a common device independent section which handles the details of file input/output, symbol table genera- tion, program/data areas, expression analysis, and assembler directive processing. The assemblers provide the following features: 1. Command string control of assembly functions 2. Alphabetized, formatted symbol table listing 3. Relocatable object modules 4. Global symbols for linking object modules 5. Conditional assembly directives THE ASSEMBLER PAGE 1-2 THE ASXXXX ASSEMBLERS 6. Program sectioning directives ASxxxx assembles one or more source files into a single relo- catable ascii object file. The output of the ASxxxx assemblers consists of an ascii relocatable object file(*.rel), an assembly listing file(*.lst), and a symbol file(*.sym). 1.1.1 Assembly Pass 1 During pass 1, ASxxxx opens all source files and performs a rudimenatry assembly of each source statement. During this pro- cess all symbol tables are built, program sections defined, and number of bytes for each assembled source line is estimated. At the end of pass 1 all undefined symbols may be made global (external) using the ASxxxx switch -g, otherwise undefined sym- bols will be flagged as errors during succeeding passes. 1.1.2 Assembly Pass 2 During pass 2 the ASxxxx assembler resolves forward refer- ences and determines the number of bytes for each assembled line. The number of bytes used by a particular assembler in- struction may depend upon the addressing mode, whether the in- struction allows multiple forms based upon the relative distance to the addressed location, or other factors. Pass 2 resolves these cases and determines the address of all symbols. 1.1.3 Assembly Pass 3 Pass 3 by the assembler generates the listing file, the relo- catable output file, and the symbol tables. Also during pass 3 the errors will be reported. The relocatable object file is an ascii file containing sym- bol references and definitions, program area definitions, and the relocatable assembled code, the linker ASLINK will use this information to generate an absolute load file (Motorola or Intel formats). THE ASSEMBLER PAGE 1-3 SOURCE PROGRAM FORMAT 1.2 SOURCE PROGRAM FORMAT 1.2.1 Statement Format A source program is composed of assembly-language statements. Each statement must be completed on one line. A line may con- tain a maximum of 128 characters, longer lines are truncated and lost. An ASxxxx assembler statement may have as many as four fields. These fields are identified by their order within the statement and/or by separating characters between fields. The general format of the ASxxxx statement is: [label:] Operator Operand [;Comment(s)] The label and comment fields are optional. The operator and operand fields are interdependent. The operator field may be an assembler directive or an assembly mnemonic. The operand field may be optional or required as defined in the context of the operator. ASxxxx interprets and processes source statements one at a time. Each statement causes a particular operation to be per- formed. 1.2.1.1 Label Field - A label is a user-defined symbol which is assigned the value of the current location counter and entered into the user de- fined symbol table. The current location counter is used by ASxxxx to assign memory addresses to the source program state- ments as they are encountered during the assembly process. Thus a label is a means of symbolically referring to a specific statement. When a program section is absolute, the value of the current location counter is absolute; its value references an absolute memory address. Similarly, when a program section is relocat- able, the value of the current location counter is relocatable. A relocation bias calculated at link time is added to the ap- parent value of the current location counter to establish its effective absolute address at execution time. (The user can also force the linker to relocate sections defined as absolute. This may be required under special circumstances.) If present, a label must be the first field in a source statement and must be terminated by a colon (:). For example, THE ASSEMBLER PAGE 1-4 SOURCE PROGRAM FORMAT if the value of the current location counter is absolute 01F0(H), the statement: abcd: nop assigns the value 01F0(H) to the label abcd. If the location counter value were relocatable, the final value of abcd would be 01F0(H)+K, where K represents the relocation bias of the program section, as calculated by the linker at link time. More than one label may appear within a single label field. Each label so specified is assigned the same address value. For example, if the value of the current location counter is 1FF0(H), the multiple labels in the following statement are each assigned the value 1FF0(H): abcd: aq: $abc: nop Multiple labels may also appear on successive lines. For ex- ample, the statements abcd: aq: $abc: nop likewise cause the same value to be assigned to all three la- bels. A double colon (::) defines the label as a global symbol. For example, the statement abcd:: nop establishes the label abcd as a global symbol. The distinguish- ing attribute of a global symbol is that it can be referenced from within an object module other than the module in which the symbol is defined. References to this label in other modules are resolved when the modules are linked as a composite execut- able image. The legal characters for defining labels are: A through Z a through z 0 through 9 . (Period) $ (Dollar sign) _ (underscore) A label may be any length, however, only the first eight (8) characters are significant and, therefore must be unique among all labels in the source program (not necessarily among THE ASSEMBLER PAGE 1-5 SOURCE PROGRAM FORMAT separately compiled modules). An error code(s) (m or p) will be generated in the assembly listing if the first eight characters in two or more labels are the same. The m code is caused by the redeclaration of the symbol or its reference by another state- ment. The p code is generated because the symbols location is changing on each pass through the source file. The label must not start with the characters 0-9, as this designates a local symbol with special attributes described in a later section. 1.2.1.2 Operator Field - The operator field specifies the action to be performed. It may consist of an instruction mnemonic (op code) or an assembler directive. When the operator is an instruction mnemonic, a machine in- struction is generated and the assembler evaluates the addresses of the operands which follow. When the operator is a directive ASxxxx performs certain control actions or processing operations during assembly of the source program. Leading and trailing spaces or tabs in the operator field have no significance; such characters serve only to separate the operator field from the preceeding and following fields. An operator is terminated by a space, tab or end of line. 1.2.1.3 Operand Field - When the operator is an instruction mnemonic (op code), the operand field contains program variables that are to be evaluated/manipulated by the operator. Operands may be expressions or symbols, depending on the operator. Multiple expressions used in the operand fields may be separated by a comma. An operand should be preceeded by an operator field; if it is not, the statement will give an error (q or o). All operands following instruction mnemonics are treated as expressions. The operand field is terminated by a semicolon when the field is followed by a comment. For example, in the following statement: label: lda abcd,x ;Comment field the tab between lda and abcd terminates the operator field and defines the beginning of the operand field; a comma separates THE ASSEMBLER PAGE 1-6 SOURCE PROGRAM FORMAT the operands abcd and x; and a semicolon terminates the operand field and defines the beginning of the comment field. When no comment field follows, the operand field is terminated by the end of the source line. 1.2.1.4 Comment Field - The comment field begins with a semicolon and extends through the end of the line. This field is optional and may contain any 7-bit ascii character except null. Comments do not affect assembly processing or program execu- tion. 1.3 SYMBOLS AND EXPRESSIONS This section describes the generic components of the ASxxxx assemblers: the character set, the conventions observed in con- structing symbols, and the use of numbers, operators, and ex- pressions. 1.3.1 Character Set The following characters are legal in ASxxxx source programs: 1. The letters A through Z. Both upper- and lower-case letters are acceptable. The assemblers are case sensi- tive, i.e. ABCD and abcd are different symbols. (The assemblers can be made case insensitive by recompiling with the appropriate switches.) 2. The digits 0 through 9 3. The characters . (period), $ (dollar sign), and _ (un- derscore). 4. The special characters listed in Tables 1 through 6. Tables 1 through 6 describe the various ASxxxx label and field terminators, assignment operators, operand separators, as- sembly, unary, binary, and radix operators. THE ASSEMBLER PAGE 1-7 SYMBOLS AND EXPRESSIONS Table 1 Label Terminators and Assignment Operators ---------------------------------------------------------------- : Colon Label terminator. :: Double colon Label Terminator; defines the label as a global label. = Equal sign Direct assignment operator. == Double equal Direct assignment operator; sign defines the symbol as a global symbol. ---------------------------------------------------------------- Table 2 Field Terminators and Operand Separators ---------------------------------------------------------------- Tab Item or field terminator. Space Item or field terminator. , Comma Operand field separator. ; Semicolon Comment field indicator. ---------------------------------------------------------------- Table 3 Assembler Operators ---------------------------------------------------------------- # Number sign Immediate expression indicator. . Period Current location counter. ( Left parenthesis Expression delimiter. ) Right parenthesis Expression delimeter. ---------------------------------------------------------------- THE ASSEMBLER PAGE 1-8 SYMBOLS AND EXPRESSIONS Table 4 Unary Operators ---------------------------------------------------------------- < Left bracket Right bracket >FEDC Produces the upper byte value of the expression. (FE) + Plus sign +A Positive value of A - Minus sign -A Produces the negative (2's complement) of A. ' Single quote 'D Produces the value of the character D. " Double quote "AB Produces the double byte value for AB. \ Backslash '\n Unix style characters \b, \f, \n, \r, \t or '\001 or octal byte values. ---------------------------------------------------------------- THE ASSEMBLER PAGE 1-9 SYMBOLS AND EXPRESSIONS Table 5 Binary Operators ---------------------------------------------------------------- << Double 0800 << 4 Produces the 4 bit Left bracket left-shifted value of 0800. (8000) >> Double 0800 >> 4 Produces the 4 bit Right bracket right-shifted value of 0800. (0080) + Plus sign A + B Arithmetic Addition operator. - Minus sign A - B Arithmetic Subtraction operator. * Asterisk A * B Arithmetic Multiplica- tion operator. (signed 16-bit) / Slash A / B Arithmetic Division operator. (signed 16-bit quotient) & Ampersand A & B Logical AND operator. | Bar A | B Logical OR operator. % Percent sign A % B Modulus operator. (16-bit value) ^ Up arrow or A ^ B EXCLUSIVE OR operator. circumflex ---------------------------------------------------------------- THE ASSEMBLER PAGE 1-10 SYMBOLS AND EXPRESSIONS Table 6 Temporary Radix Operators ---------------------------------------------------------------- 0b, 0B Binary radix operator. 0@, 0o, 0O, 0q, 0Q Octal radix operator. 0d, 0D Decimal radix operator. 0h, 0H, 0x, 0X Hexidecimal radix operator. ---------------------------------------------------------------- 1.3.2 User-Defined Symbols User-defined symbols are those symbols that are equated to a specific value through a direct assignment statement or appear as labels. These symbols are added to the User Symbol Table as they are encountered during assembly. The following rules govern the creation of user-defined symbols: 1. Symbols can be composed of alphanumeric characters, dollar signs ($), periods (.), and underscores (_) only. 2. The first character of a symbol must not be a number (except in the case of local symbols). 3. The first eight characters of a symbol must be unique. A symbol can be written with more than eight legal characters, but the ninth and subsequent characters are ignored. 4. Spaces and Tabs must not be embedded within a symbol. THE ASSEMBLER PAGE 1-11 SYMBOLS AND EXPRESSIONS 1.3.3 Local Symbols Local symbols are specially formatted symbols used as labels within a block of coding that has been delimited as a local sym- bol block. Local symbols are of the form n$, where n is a decimal integer from 0 to 255, inclusive. Examples of local symbols are: 1$ 27$ 138$ 244$ The range of a local symbol block consists of those state- ments between two normally constructed symbolic labels. Note that a statement of the form: ALPHA = EXPRESSION is a direct assignment statement but does not create a label and thus does not delimit the range of a local symbol block. Note that the range of a local symbol block may extend across program areas. Local symbols provide a convenient means of generating labels for branch instructions and other such references within local symbol blocks. Using local symbols reduces the possibility of symbols with multiple definitions appearing within a user pro- gram. In addition, the use of local symbols differentiates entry-point labels from local labels, since local labels cannot be referenced from outside their respective local symbol blocks. Thus, local symbols of the same name can appear in other local symbol blocks without conflict. Local symbols require less sym- bol table space than normal symbols. Their use is recommended. The use of the same local symbol within a local symbol block will generate one or both of the m or p errors. THE ASSEMBLER PAGE 1-12 SYMBOLS AND EXPRESSIONS Example of local symbols: a: ldx #atable ;get table address lda #0d48 ;table length 1$: clr ,x+ ;clear deca bne 1$ b: ldx #btable ;get table address lda #0d48 ;table length 1$: clr ,x+ ;clear deca bne 1$ 1.3.4 Current Location Counter The period (.) is the symbol for the current location coun- ter. When used in the operand field of an instruction, the period represents the address of the first byte of the instruction: AS: ldx #. ;The period (.) refers to ;the address of the ldx ;instruction. When used in the operand field of an ASxxxx directive, it represents the address of the current byte or word: QK = 0 .word 0xFFFE,.+4,QK ;The operand .+4 in the .word ;directive represents a value ;stored in the second of the ;three words during assembly. If we assume the current value of the program counter is 0H0200, then during assembly, ASxxxx reserves three words of storage starting at location 0H0200. The first value, a hex- idecimal constant FFFE, will be stored at location 0H0200. The second value represented by .+4 will be stored at location 0H0202, its value will be 0H0206 ( = 0H0202 + 4). The third value defined by the symbol QK will be placed at location 0H0204. At the beginning of each assembly pass, ASxxxx resets the lo- cation counter. Normally, consecutive memory locations are as- signed to each byte of object code generated. However, the value of the location counter can be changed through a direct assignment statement of the following form: THE ASSEMBLER PAGE 1-13 SYMBOLS AND EXPRESSIONS . = . + expression The new location counter can only be specified relative to the current location counter. Neglecting to specify the current program counter along with the expression on the right side of the assignment operator will generate the (.) error. (Absolute program areas may use the .org directive to specify the absolute location of the current program counter.) The following coding illustrates the use of the current location counter: .area CODE1 (ABS) ;program area CODE1 ;is ABSOLUTE .org 0H100 ;set location to ;0H100 absolute num1: ldx #.+0H10 ;The label num1 has ;the value 0H100. ;X is loaded with ;0H100 + 0H10 .org 0H130 ;location counter ;set to 0H130 num2: ldy #. ;The label num2 has ;the value 0H130. ;Y is loaded with ;value 0H130. .area CODE2 (REL) ;program area CODE2 ;is RELOCATABLE . = . + 0H20 ;Set location counter ;to relocatable 0H20 of ;the program section. num3: .word 0 ;The label num3 has ;the value ;of relocatable 0H20. . = . + 0H40 ;will reserve 0H40 ;bytes of storage as will .blkb 0H40 ;or .blkw 0H20 The .blkb and .blkw directives are the preferred methods of allocating space. THE ASSEMBLER PAGE 1-14 SYMBOLS AND EXPRESSIONS 1.3.5 Numbers ASxxxx assumes that all numbers in the source program are to be interpreted in decimal radix unless otherwise specified. The .radix directive may be used to specify the default as octal, decimal, or hexidecimal. Individual numbers can be designated as binary, octal, decimal, or hexidecimal through the temporary radix prefixes shown in table 6. Negative numbers must be preceeded by a minus sign; ASxxxx translates such numbers into two's complement form. Positive numbers may (but need not) be preceeded by a plus sign. Numbers are always considered to be absolute values, therefor they are never relocatable. 1.3.6 Terms A term is a component of an expression and may be one of the following: 1. A number. 2. A symbol: 1. A period (.) specified in an expression causes the current location counter to be used. 2. A User-defined symbol. 3. An undefined symbol is assigned a value of zero and inserted in the User-Defined symbol table as an un- defined symbol. 3. A single quote followed by a single ascii character, or a double quote followed by two ascii characters. 4. An expression enclosed in parenthesis. Any expression so enclosed is evaluated and reduced to a single term before the remainder of the expression in which it ap- pears is evaluated. Parenthesis, for example, may be used to alter the left-to-right evaluation of expres- sions, (as in A*B+C versus A*(B+C)), or to apply a un- ary operator to an entire expression (as in -(A+B)). 5. A unary operator followed by a symbol or number. THE ASSEMBLER PAGE 1-15 SYMBOLS AND EXPRESSIONS 1.3.7 Expressions Expressions are combinations of terms joined together by binary operators. Expressions reduce to a 16-bit value. The evaluation of an expression includes the determination of its attributes. A resultant expression value may be one of three types (as described later in this section): relocatable, ab- solute, and external. Expressions are evaluate with an operand hierarchy as follows: * / % multiplication, division, and modulus first. + - addition and subtraction second. << >> left shift and right shift third. ^ exclusive or fourth. & logical and fifth. | logical or last except that unary operators take precedence over binary operators. A missing or illegal operator terminates the expression analysis, causing error codes (o) and/or (q) to be generated depending upon the context of the expression itself. At assembly time the value of an external (global) expression is equal to the value of the absolute part of that expression. For example, the expression external+4, where 'external' is an external symbol, has the value of 4. This expression, however, when evaluated at link time takes on the resolved value of the symbol 'external', plus 4. Expressions, when evaluated by ASxxxx, are one of three types: relocatable, absolute, or external. The following dis- tinctions are important: 1. An expression is relocatable if its value is fixed re- lative to the base address of the program area in which it appears; it will have an offset value added at link time. Terms that contain labels defined in relocatable program areas will have a relocatable value; THE ASSEMBLER PAGE 1-16 SYMBOLS AND EXPRESSIONS similarly, a period (.) in a relocatable program area, representing the value of the current program location counter, will also have a relocatable value. 2. An expression is absolute if its value is fixed. An expression whose terms are numbers and ascii characters will reduce to an absolute value. A relocatable ex- pression or term minus a relocatable term, where both elements being evaluated belong to the same program area, is an absolute expression. This is because every term in a program area has the same relocation bias. When one term is subtracted from the other the reloca- tion bias is zero. 3. An expression is external (or global) if it contains a single global reference (plus or minus an absolute ex- pression value) that is not defined within the current program. Thus, an external expression is only par- tially defined following assembly and must be resolved at link time. 1.4 GENERAL ASSEMBLER DIRECTIVES An ASxxxx directive is placed in the operator field of the source line. Only one directive is allowed per source line. Each directive may have a blank operand field or one or more operands. Legal operands differ with each directive. 1.4.1 .module Directive Format: .module string The .module directive causes the string to be included in the assemblers output file as an identifier for this particular ob- ject module. The string may be from 1 to 8 characters in length. Only one identifier is allowed per assembled module. The main use of this directive is to allow the linker to report a modules' use of undefined symbols. At link time all undefined symbols are reported and the modules referencing them are listed. THE ASSEMBLER PAGE 1-17 GENERAL ASSEMBLER DIRECTIVES 1.4.2 .title Directive Format: .title string The .title directive provides a character string to be placed on the second line of each page during listing. 1.4.3 .sbttl Directive Format: .sbttl string The .sbttl directive provides a character string to be placed on the third line of each page during listing. 1.4.4 .page Directive Format: .page The .page directive causes a page ejection with a new heading to be printed. The new page occurs after the next line of the source program is processed, this allows an immediately follow- ing .sbttl directive to appear on the new page. The .page source line will not appear in the file listing. 1.4.5 .byte and .db Directives Format: .byte exp ;Stores the binary value .db exp ;of the expression in the ;next byte. .byte exp1,exp2,expn ;Stores the binary values .db exp1,exp2,expn ;of the list of expressions ;in successive bytes. where: exp, represent expressions that will be exp1, truncated to 8-bits of data. . Each expression will be calculated . as a 16-bit word expression, . the high-order byte will be truncated. . Multiple expressions must be expn separated by commas. THE ASSEMBLER PAGE 1-18 GENERAL ASSEMBLER DIRECTIVES The .byte or .db directives are used to generate successive bytes of binary data in the object module. 1.4.6 .word and .dw Directives Format: .word exp ;Stores the binary value .dw exp ;of the expression in ;the next word. .word exp1,exp2,expn ;Stores the binary values .dw exp1,exp2,expn ;of the list of expressions ;in successive words. where: exp, represent expressions that will occupy two exp1, bytes of data. Each expression will be . calculated as a 16-bit word expression. . Multiple expressions must be expn separated by commas. The .word or .dw directives are used to generate successive words of binary data in the object module. 1.4.7 .blkb, .blkw, and .ds Directives Format: .blkb N ;reserve N bytes of space .blkw N ;reserve N words of space .ds N ;reserve N bytes of space The .blkb and .ds directives reserve byte blocks in the ob- ject module; the .blkw directive reserves word blocks. 1.4.8 .ascii Directive Format: .ascii /string/ where: string is a string of printable ascii characters. / / represent the delimiting characters. These delimiters may be any paired printing characters, as long as the characters are not contained within the string itself. If the delimiting characters do not match, the .ascii directive will give the (q) error. THE ASSEMBLER PAGE 1-19 GENERAL ASSEMBLER DIRECTIVES The .ascii directive places one binary byte of data for each character in the string into the object module. 1.4.9 .asciz Directive Format: .asciz /string/ where: string is a string of printable asciz characters. / / represent the delimiting characters. These delimiters may be any paired printing characters, as long as the characters are not contained within the string itself. If the delimiting characters do not match, the .asciz directive will give the (q) error. The .ascii directive places one binary byte of data for each character in the string into the object module. Following all the character data a zero byte is inserted to terminate the character string. 1.4.10 .radix Directive Format: .radix character where: character represents a single character specifying the default radix to be used for succeeding numbers. The character may be any one of the following: B,b Binary O,o Octal Q,q @ D,d Decimal 'blank' H,h Hexidecimal X,x THE ASSEMBLER PAGE 1-20 GENERAL ASSEMBLER DIRECTIVES 1.4.11 .even Directive Format: .even The .even directive ensures that the current location counter contains an even boundary value by adding 1 if the current loca- tion is odd. 1.4.12 .odd Directive Format: .odd The .odd directive ensures that the current location counter contains an odd boundary value by adding one if the current lo- cation is even. 1.4.13 .area Directive Format: .area name [(options)] where: name represents the symbolic name of the program sec- tion. This name may be the same as any user-defined symbol as the area names are in- dependent of all symbols and labels. options specify the type of program or data area: ABS absolute (automatically invokes OVR) REL relocatable OVR overlay CON concatenate The .area directive provides a means of defining and separat- ing multiple programming and data sections. The name is the area label used by the assembler and the linker to collect code from various separately assembled modules into one section. The name may be from 1 to 8 characters in length. The options are specified within parenthesis and separated by commas as shown in the following example: .area TEST (REL,CON) ;This section is relocatable ;and concatenated with other ;sections of this program area. THE ASSEMBLER PAGE 1-21 GENERAL ASSEMBLER DIRECTIVES .area DATA (REL,OVR) ;This section is relocatable ;and overlays other sections ;of this program area. .area SYS (ABS,OVR) ;(CON not allowed with ABS) ;This section is defined as ;absolute. Absolute sections ;are always overlayed with ;other sections of this program ;area. The default area type is REL|CON; i.e. a relocatable sec- tion which is concatenated with other sections of code with the same area name. The ABS option indicates an absolute area. The OVR and CON options indicate if program sections of the same name will overlay each other (start at the same location) or be concatenated with each other (appended to each other). Multiple invocations of the .area directive with the same name must specify the same options or leave the options field blank, this defaults to the previously specified options for this program area. The ASxxxx assemblers automatically provide two program sections: '. .ABS.' This dumby section contains all absolute symbols and their values. '_CODE' This is the default program/data area. This program area is of type (REL,CON). 1.4.14 .org Directive Format: .org exp where: exp is an absolute expression that becomes the cur- rent location counter. The .org directive is valid only in an absolute program section and will give a (q) error if used in a relocatable program area. The .org directive specifies that the current location counter is to become the specified absolute value. THE ASSEMBLER PAGE 1-22 GENERAL ASSEMBLER DIRECTIVES 1.4.15 .globl Directive Format: .globl sym1,sym2,...,symn where: sym1, represent legal symbolic names. When sym2,... When multiple symbols are specified, symn they are separated by commas. A .globl directive may also have a label field and/or a com- ment field. The .globl directive is provided to define (and thus provide linkage to) symbols not otherwise defined as global symbols within a module. In defining global symbols the directive .globl J is similar to: J == expression or J:: Because object modules are linked by global symbols, these symbols are vital to a program. All internal symbols appearing within a given program must be defined at the end of pass 1 or they will be considered undefined. The assembly directive (-g) can be be invoked to make all undefined symbols global at the end of pass 1. 1.4.16 .if, .else, and .endif Directives Format: .if expr . ;} . ;} range of true condition . ;} .else . ;} . ;} range of false condition . ;} .endif The conditional assembly directives allow you to include or exclude blocks of source code during the assembly process, based on the evaluation of the condition test. The range of true condition will be processed if the expres- sion 'expr' is not zero (i.e. true) and the range of false con- dition will be processed if the expression 'expr' is zero (i.e false). The range of true condition is optional as is the .else directive and the range of false condition. The following are all valid .if/.else/.endif constructions: THE ASSEMBLER PAGE 1-23 GENERAL ASSEMBLER DIRECTIVES .if A-4 ;evaluate A-4 .byte 1,2 ;insert bytes if A-4 is .endif ;not zero .if K+3 ;evaluate K+3 .else .byte 3,4 ;insert bytes if K+3 .endif ;is zero .if J&3 ;evaluate J masked by 3 .byte 12 ;insert this byte if J&3 .else ;is not zero .byte 13 ;insert this byte if J&3 .endif ;is zero The .if/.else/.endif directives may be nested upto 10 levels. The .page directive is processed within a false condition range to allow extended textual information to be incorporated in the source program with out the need to use the comment delimiter (;): .if 0 .page This text will be bypassed during assembly but appear in the listing file. . . . .endif 1.4.17 .include Directive Format: .include string where: string represents a delimited string that is the file specification of an ASxxxx source file. The .include directive is used to insert a source file within the source file currently being assembled. When this directive is encountered, an implicit .page directive is issued. When the end of the specified source file is reached, an implicit .page directive is issued and input continues from the previous source file. The maximum nesting level of source files specified by a THE ASSEMBLER PAGE 1-24 GENERAL ASSEMBLER DIRECTIVES .include directive is five. The line containing the .include directive will not appear in the listing file. The total number of separately specified .include files is unlimited as each .include file is opened and then closed during each pass made by the assembler. 1.5 INVOKING ASXXXX The ASxxxx assemblers are command line oriented. After the assembler is started, enter the option(s) and file(s) to assem- ble following the 'argv:' prompt: argv: [-dqxgalos] file1 [file2 file3 ... file6] The options are: d decimal listing q octal listing x hex listing (default) The listing radix affects the .lst, .rel, and .sym files. g undefined symbols made global a all user symbols made global l create list output file1.lst o create object output file1.rel s create symbol output file1.sym The file name for .lst, .rel, and .sym files is the first file name specified in the command line. All output files are ascii text files which may be edited, copied, etc. The output files are the concatenation of all the input files, if files are to be assembled independently invoke the assembler for each file. The .rel file contains a radix directive so that the linker will use the proper conversion for this file. Linked files may have different radices. If the list (l) option is specified without the symbol table (s) option, the symbol table is placed at the end of the listing file. THE ASSEMBLER PAGE 1-25 ERRORS 1.6 ERRORS The ASxxxx assemblers provide limited diagnostic error codes during the assembly process, these errors will be noted in the listing file and printed on the stderr device. The errors are: (.) This error is caused by an absolute direct assign- ment of the current location counter . = expression (incorrect) rather than the correct . = . + expression (a) Indicates a machine specific addressing or address- ing mode error. (i) Caused by an .include file error or an .if/.endif mismatch. (m) Multiple definitions of the same label, multiple .module directives, or multiple conflicting attri- butes in an .area directive. (o) Directive or mnemonic error or the use of the .org directive in a relocatable area. (p) Phase error: label location changing between passes 2 and 3. Normally caused by having more than one level of forward referencing. (q) Questionable syntax: missing or improper operators, terminators, or delimiters. (r) Relocation error: logic operation attempted on a relocatable term, addition of two relocatable terms, subtraction of two relocatable terms not within the same programming area or external symbols. (u) Undefined symbol encountered during assembly. THE ASSEMBLER PAGE 1-26 LISTING FILE 1.7 LISTING FILE The (-l) option produces an ascii output listing file. Each page of output contains a four line header: 1. The ASxxxx program name and page number 2. Title from a .title directive (if any) 3. Subtitle from a .sbttl directive (if any) 4. Blank line Each succeeding line contains five fields: 1. Error field (first three characters of line) 2. Current location counter 3. Generated code in byte format 4. Source text line number 5. Source text The error field may contain upto 3 error flags indicating any errors encountered while assembling this line of source code. The current location counter field displays the 16-bit pro- gram position. This field will be in the selected radix. The generated code follows the program location. The listing radix determines the number of bytes that will be displayed in this field. Hexidecimal listing allows six bytes of data within the field, decimal and octal allow four bytes within the field. If more than one field of data is generated from the assembly of a single line of source code, then the data field is repeated on successive lines. The source text line number is printed in decimal and is fol- lowed by the source text. Two special cases will disable the listing of a line of source text: THE ASSEMBLER PAGE 1-27 LISTING FILE 1. Source line with a .page directive is never listed. 2. Source line with a .include file directive is not listed unless the .include file cannot be opened. 1.8 SYMBOL TABLE FILE The symbol table has two parts: 1. The alphabetically sorted list of symbols and/or labels defined or referenced in the source program. 2. A list of the program areas defined during assembly of the source program. The sorted list of symbols and/or labels contains the follow- ing information: 1. Program area number (none if absolute value or exter- nal) 2. The symbol or label 3. Directly assigned symbol is denoted with an (=) sign 4. The value of a symbol, location of a label relative to the program area base address (=0), or a **** indicat- ing the symbol or label is undefined. 5. The characters: G - global, R - relocatable, and X - external. The list of program areas provides the correspondence between the program area numbers and the defined program areas, the size of the program areas, and the area flags (attributes). THE ASSEMBLER PAGE 1-28 OBJECT FILE 1.9 OBJECT FILE The object file is an ascii file containing the information needed by the linker to bind multiple object modules into a com- plete loadable memory image. The object module contains the following designators: [XDQ][HL] X Hexidecimal radix D Decimal radix Q Octal radix H Most significant byte first L Least significant byte first H Header M Module A Area S Symbol T Object code R Relocation information Refer to the linker for a detailed description of each of the designators and the format of the information contained in the object file. CHAPTER 2 THE LINKER 2.1 ASLINK RELOCATING LINKER ASLINK is the companion linker for the ASxxxx assemblers. The program ASLINK is a general relocating linker performing the following functions: 1. Bind multiple object modules into a single memory image 2. Resolve inter-module symbol references 3. Combine code belonging to the same area from multiple object files into a single contiguous memory region 4. Perform byte and word program counter relative (pc or pcr) addressing calculations 5. Define absolute symbol values at link time 6. Define absolute area base address values at link time 7. Produce Intel Hex or Motorola S19 output file 8. Produce a map of the linked memory image THE LINKER PAGE 2-2 INVOKING ASLINK 2.2 INVOKING ASLINK The linker may run in the command line mode or command file modes. The allowed startup linker commands are: -c/-f command line / command file modes -p/-n enable/disable echo file.lnk input to stdout If command line mode is selected, all linker commands come from stdin, if the command file mode is selected the commands are input from the specified file (extension must be .lnk). The linker is started via ASLINK -(cfpn) After invoking the linker the valid options are: 1. -i/-s Intel Hex (file.ihx) or Motorola S19 (file.s19) image output file. 2. -m Generate a map file (file.map). This file con- tains a list of the symbols (by area) with absolute ad- dresses, sizes of linked areas, and other linking information. 3. -xdq Specifies the number radix for the map file (Hexidecimal, Decimal, or Octal). 4. fileN Files to be linked. Files may be on the same line as the above options or on a separate line(s) one file per line or multiple files separated by spaces or tabs. 5. -b area = expression (one definition per line) This specifies an area base address where the expres- sion may contain constants and/or defined symbols from the linked files. 6. -g symbol = expression (one definition per line) This specifies the value for the symbol where the ex- pression may contain constants and/or defined symbols from the linked files. 7. -e or null line, terminates input to the linker. THE LINKER PAGE 2-3 ASLINK PROCESSING 2.3 ASLINK PROCESSING The linker processes the files in the order they are presented. The first pass through the input files is used to define all program areas, the section area sizes, and symbols defined or referenced. After the first pass the -b (area base address) definitions, if any, are processed and the areas linked. The area linking proceeds by first examining the area types ABS, CON, REL, and OVR. Absolute areas (ABS) from separate ob- ject modules are always overlayed and have been assembled at a specific address, these are not normally relocated (if a -b com- mand is used on an absolute area the area will be relocated). Relative areas (normally defined as REL|CON) have a base address of 0x0000 as read from the object files, the -b command speci- fies the beginning address of the area. All subsequent relative areas will be concatenated with proceeding relative areas. Where specific ordering is desired, the first linker input file should have the area definitions in the desired order. At the completion of the area linking all area addresses and lengths have been determined. Next the global symbol definitions (-g option), if any, are processed. The symbol definitions have been delayed until this point because the absolute addresses of all internal symbols are known and can be used in the expression calculations. Before continuing with the linking process the symbol table is scanned to determine if any symbols have been referenced but not defined. Undefined symbols are listed on the stderr device. if a .module directive was included in the assembled file the module making the reference to this undefined variable will be printed. Constants defined as global in more than one module will be flagged as multiple definitions if their values are not identi- cal. After the preceeding processes are complete the linker may output a map file (-m option). This file provides the following information: 1. Global symbol values and label absolute addresses 2. Defined areas and there lengths 3. Remaining undefined symbols 4. List of modules linked THE LINKER PAGE 2-4 ASLINK PROCESSING 5. List of -b and -g definitions The final step of the linking process is performed during the second pass of the input files. As the xxx.rel files are read the code is relocated by substituting the physical addresses for the referenced symbols and areas and may be output in Intel or Motorola formats. The number of files linked and symbols de- fined/referenced is limited by the processor space available to build the area/symbol lists. 2.4 LINKER INPUT FORMAT The linkers' input object file is an ascii file containing the information needed by the linker to bind multiple object modules into a complete loadable memory image. The object module contains the following designators: [XDQ][HL] X Hexidecimal radix D Decimal radix Q Octal radix H Most significant byte first L Least significant byte first H Header M Module A Area S Symbol T Object code R Relocation information 2.4.1 Object Module Format The first line of an object module contains the [XDQ][HL] format specifier (i.e. XH indicates a hexidecimal file with most significant byte first) for the following designators. THE LINKER PAGE 2-5 LINKER INPUT FORMAT 2.4.2 Header Line H aa areas gg global symbols The header line specifies the number of areas(aa) and the number of global symbols(gg) defined or referenced in this ob- ject module segment. 2.4.3 Module Line M name The module line specifies the module name from which this header segment was assembled. The module line will not appear if the .module directive was not used in the source program. 2.4.4 Symbol Line S string Defnnnn or S string Refnnnn The symbol line defines (Def) or references (Ref) the symbol 'string' with the value nnnn. The defined value is relative to the current area base address. References to constants and ex- ternal global symbols will always appear before the first area definition. References to external symbols will have a value of zero. 2.4.5 Area Line A label size ss flags ff The area line defines the area label, the size (ss) of the area in bytes, and the area flags (ff). The area flags specify the ABS, REL, CON, and OVR parameters: OVR/CON (0x04/0x00 i.e. bit position 2) ABS/REL (0x08/0x00 i.e. bit position 3) THE LINKER PAGE 2-6 LINKER INPUT FORMAT 2.4.6 T Line T xx xx nn nn nn nn nn ... The T line contains the assembled code output by the assem- bler with xx xx being the offset address from the current area base address and nn being the assembled instructions and data in byte format. 2.4.7 R Line R 0 0 nn nn n1 n2 xx xx ... The R line provides the relocation information to the linker. The nn nn value is the current area index, i.e. which area the current relocation references. Relocation information is en- coded in groups of 4 bytes: 1. n1 is the relocation mode 1. bit 0 word(0x00)/byte(0x01) 2. bit 1 relocatable area(0x00)/symbol(0x02) 3. bit 2 normal(0x00)/PC relative(0x04) relocation 2. n2 is a byte index into the corresponding (i.e. pre- ceeding) T line data (i.e. a pointer to the data to be updated by the relocation) 3. xx xx is the area/symbol index for the area/symbol be- ing referenced. the corresponding area/symbol is found in the header area/symbol lists. The groups of 4 bytes are repeated for each item requiring relo- cation in the preceeding T line. CHAPTER 3 BUILDING ASXXXX AND ASLINK The assemblers and linker have been successfully compiled us- ing the DECUS C compiler (patch level 9) with RT-11/TSX+ and with Borland's Turbo C V1.5 with MS-DOS. The only difference is the definition of 'VOID' (contained in asm.h and aslink.h) as 'char' in DECUS C and as 'void' in Turbo C. The device specific header file (i.e. 6800.h, 6801.h, etc.) contains the DECUS C 'BUILD' directives for generating a command file to compile, assemble, and link the necessary files to pre- pare an executable image for a particular assembler. 3.1 BUILDING AN ASSEMBLER The building of a typical assembler (6809 for example) re- quires the following files: 1. 6809.H 2. M09EXT.C 3. M09MCH.C 4. M09ADR.C 5. M09PST.C 6. ASM.H 7. ASMAIN.C 8. ASLEX.C 9. ASSYM.C 10. ASSUBR.C 11. ASEXPR.C 12. ASDATA.C 13. ASLIST.C 14. ASOUT.C The first five files are the 6809 processor dependent sec- tions which contain the following: BUILDING ASXXXX AND ASLINK PAGE 3-2 BUILDING AN ASSEMBLER 1. 6809.h - header file containing the machine specific definitions of constants, variables, structures, and types 2. m09ext - device description, byte order, and file ex- tension information 3. m09pst - a table of the assembler general directives, special device directives, and assembler mnemonics with associated operation codes 4. m09mch / m09adr - machine specific code for processing the device mnemonics, addressing modes, and special directives The remaining nine files provide the device independent sec- tions which handle the details of file input/output, symbol table generation, program/data areas, expression analysis, and assembler directive processing. The assembler defaults to the case sensitive mode. This may be altered by changing the case sensitivity flag in asm.h to /* * Case Sensitivity Flag */ #define CASE_SENSITIVE 0 The assemblers and linker should be compiled with the same case sensitivity option. The DECUS C build files are asxxxx.bld and the Turbo C pro- ject files are asxxxx.prj. 3.2 BUILDING ASLINK The building of the linker requires the following files: 1. ASLINK.H 2. LKMAIN.C 3. LKLEX.C 4. LKAREA.C 5. LKHEAD.C 6. LKSYM.C 7. LKEVAL.C 8. LKDATA.C 9. LKLIST.C 10. LKRLOC.C BUILDING ASXXXX AND ASLINK PAGE 3-3 BUILDING ASLINK 11. LKS19.C 12. LKIHX.C The linker defaults to the case sensitive mode. This may be altered by changing the case sensitivity flag in aslink.h to /* * Case Sensitivity Flag */ #define CASE_SENSITIVE 0 The linker and assemblers should be compiled with the same case sensitivity option. The DECUS C build file is aslink.bld and the Turbo C project file is aslink.prj. APPENDIX A AS6800 ASSEMBLER A.1 .setdp DIRECTIVE Format: .setdp [area] The .setdp directive informs the assembler in which area the direct page is located. If the optional area name is left blank, then the current area is defined as containing the direct page. If a .setdp directive is not issued the assembler defaults the direct page to the area "_CODE". The .setdp direc- tive is required when using the relocation features so that the direct page space may be independently positioned at link time. The assembler verifies that any variable referenced as a direct variable is located in this area and has a value from 0 to 255. A.2 6800 REGISTER SET The following is a list of the 6800 registers used by AS6800: a,b - 8-bit accumulators x - index register AS6800 ASSEMBLER PAGE A-2 6800 INSTRUCTION SET A.3 6800 INSTRUCTION SET The following tables list all 6800/6802/6808 mnemonics recog- nized by the AS6800 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by AS6800: #data immediate data byte or word data *dir direct page addressing (see .setdp directive) 0 <= dir <= 255 (the value of dir must be defined within the current assembly) ,x register indirect addressing zero offset offset,x register indirect addressing 0 <= offset <= 255 (the value of offset must be defined within the current assembly) ext extended addressing label branch label The terms data, dir, offset, ext, and label may all be expres- sions. The terms dir, offset, and label are not allowed to be external references. Note that not all addressing modes are valid with every in- struction, refer to the 6800 technical data for valid modes. AS6800 ASSEMBLER PAGE A-3 6800 INSTRUCTION SET A.3.1 Inherent Instructions aba cba clc cli clv daa des dex ins inx nop rti rts sba sec sei sev swi tab tap tba tpa tsx txs wai psha pshb psh a psh b pula pulb pul a pul b A.3.2 Branch Instructions bra label bhi label bls label bcc label bhs label bcs label blo label bne label beq label bvc label bvs label bpl label bmi label bge label blt label bgt label ble label bsr label AS6800 ASSEMBLER PAGE A-4 6800 INSTRUCTION SET A.3.3 Single Operand Instructions asla aslb asl a asl b asl [] asra asrb asr a asr b asr [] clra clrb clr a clr b clr [] coma comb com a com b com [] deca decb dec a dec b dec [] inca incb inc a inc b inc [] lsla lslb lsl a lsl b lsl [] lsra lsrb lsr a lsr b lsr [] nega negb neg a neg b neg [] rola rolb rol a rol b rol [] rora rorb ror a ror b ror [] tsta tstb tst a tst b tst [] AS6800 ASSEMBLER PAGE A-5 6800 INSTRUCTION SET A.3.4 Double Operand Instructions adca [] adcb [] adc a [] adc b [] adda [] addb [] add a [] add b [] anda [] andb [] and a [] and b [] bita [] bitb [] bit a [] bit b [] cmpa [] cmpb [] cmp a [] cmp b [] eora [] eorb [] eor a [] eor b [] ldaa [] ldab [] lda a [] lda b [] oraa [] orab [] ora a [] ora b [] sbca [] sbcb [] sbc a [] sbc b [] staa [] stab [] sta a [] sta b [] suba [] subb [] sub a [] sub b [] A.3.5 Jump and Jump to Subroutine Instructions jmp [] jsr [] AS6800 ASSEMBLER PAGE A-6 6800 INSTRUCTION SET A.3.6 Long Register Instructions cpx [] lds [] sts [] ldx [] stx [] APPENDIX B AS6801 ASSEMBLER B.1 .setdp DIRECTIVE Format: .setdp [area] The .setdp directive informs the assembler in which area the direct page is located. If the optional area name is left blank, then the current area is defined as containing the direct page. If a .setdp directive is not issued the assembler defaults the direct page to the area "_CODE". The .setdp direc- tive is required when using the relocation features so that the direct page space may be positioned properly at link time. The assembler verifies that any variable referenced as a direct variable is located in this area and has a value from 0 to 255. B.2 .hd6303 DIRECTIVE Format: .hd6303 The .hd6303 directive enables processing of the HD6303 specific mnemonics not included in the 6801 instruction set. HD6303 mnemonics encountered without the .hd6303 directive will be flagged with an 'o' error. AS6801 ASSEMBLER PAGE B-2 6801 REGISTER SET B.3 6801 REGISTER SET The following is a list of the 6801 registers used by AS6801: a,b - 8-bit accumulators d - 16-bit accumulator x - index register B.4 6801 INSTRUCTION SET The following tables list all 6801/6303 mnemonics recognized by the AS6801 assembler. The designation [] refers to a re- quired addressing mode argument. The following list specifies the format for each addressing mode supported by AS6801: #data immediate data byte or word data *dir direct page addressing (see .setdp directive) 0 <= dir <= 255 (the value of dir must be defined within the current assembly) ,x register indirect addressing zero offset offset,x register indirect addressing 0 <= offset <= 255 (the value of offset must be defined within the current assembly) ext extended addressing label branch label The terms data, dir, offset, ext, and label may all be expres- sions. The terms dir, offset, and label are not allowed to be external references. Note that not all addressing modes are valid with every in- struction, refer to the 6801/6303 technical data for valid modes. AS6801 ASSEMBLER PAGE B-3 6801 INSTRUCTION SET B.4.1 Inherent Instructions aba abx cba clc cli clv daa des dex ins inx mul nop rti rts sba sec sei sev swi tab tap tba tpa tsx txs wai B.4.2 Branch Instructions bra label brn label bhi label bls label bcc label bhs label bcs label blo label bne label beq label bvc label bvs label bpl label bmi label bge label blt label bgt label ble label bsr label B.4.3 Single Operand Instructions asla aslb asld asl a asl b asl d asl [] asra asrb asr a asr b asr [] clra clrb clr a clr b clr [] coma comb com a com b com [] deca decb dec a dec b AS6801 ASSEMBLER PAGE B-4 6801 INSTRUCTION SET dec [] eora eorb eor a eor b eor [] inca incb inc a inc b inc [] lsla lslb lsld lsl a lsl b lsl d lsl [] lsra lsrb lsrd lsr a lsr b lsr d lsr [] nega negb neg a neg b neg [] psha pshb pshx psh a psh b psh x pula pulb pulx pul a pul b pul x rola rolb rol a rol b rol [] rora rorb ror a ror b ror [] tsta tstb tst a tst b tst [] AS6801 ASSEMBLER PAGE B-5 6801 INSTRUCTION SET B.4.4 Double Operand Instructions adca [] adcb [] adc a [] adc b [] adda [] addb [] addd [] add a [] add b [] add d [] anda [] andb [] and a [] and b [] bita [] bitb [] bit a [] bit b [] cmpa [] cmpb [] cmp a [] cmp b [] ldaa [] ldab [] lda a [] lda b [] oraa [] orab [] ora a [] ora b [] sbca [] sbcb [] sbc a [] sbc b [] staa [] stab [] sta a [] sta b [] suba [] subb [] subd [] sub a [] sub b [] sub d [] B.4.5 Jump and Jump to Subroutine Instructions jmp [] jsr [] B.4.6 Long Register Instructions cpx [] ldd [] lds [] ldx [] std [] sts [] stx [] AS6801 ASSEMBLER PAGE B-6 6801 INSTRUCTION SET B.4.7 6303 Specific Instructions aim #data, [] eim #data, [] oim #data, [] tim #data, [] xgdx slp APPENDIX C AS6804 ASSEMBLER Because the 6804 has only a 256 byte ram space the .setdp directive is not supported. C.1 6804 REGISTER SET The following is a list of the 6804 registers used by AS6804: x,y - index registers C.2 6804 INSTRUCTION SET The following tables list all 6804 mnemonics recognized by the AS6804 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by AS6804: #data immediate data byte or word data ,x register indirect addressing dir direct addressing 0 <= dir <= 255 ext extended addressing label branch label The terms data, dir, and ext may be expressions. The terms dir and label are not allowed to be external references. Note that not all addressing modes are valid with every in- struction, refer to the 6804 technical data for valid modes. AS6804 ASSEMBLER PAGE C-2 6804 INSTRUCTION SET C.2.1 Inherent Instructions coma decx decy incx incy rola rti rts stop tax tay txa tya wait C.2.2 Branch Instructions bne label beq label bcc label bcs label C.2.3 Single Operand Instructions add [] and [] cmp [] dec [] inc [] lda [] sta [] sub [] C.2.4 Jump and Jump to Subroutine Instructions jsr [] jmp [] C.2.5 Bit Test Instructions brclr #data,[],label brset #data,[],label bclr #label,[] bset #label,[] AS6804 ASSEMBLER PAGE C-3 6804 INSTRUCTION SET C.2.6 Load Immediate data Instruction mvi [],#data C.2.7 6804 Derived Instructions asla bam label bap label bxmi label bxpl label bymi label bypl label clra clrx clry deca decx decy inca incx incy ldxi #data ldyi #data nop tax tay txa tya APPENDIX D AS6805 ASSEMBLER D.1 .setdp DIRECTIVE Format: .setdp [area] The .setdp directive informs the assembler in which area the direct page is located. If the optional area name is left blank, then the current area is defined as containing the direct page. If a .setdp directive is not issued the assembler defaults the direct page to the area "_CODE". The .setdp direc- tive is required when using the relocation features so that the direct page space may be positioned properly at link time. The assembler verifies that any variable referenced as a direct variable is located in this area and has a value from 0 to 255. D.2 6805 REGISTER SET The following is a list of the 6805 registers used by AS6805: a - 8-bit accumulator x - index register AS6805 ASSEMBLER PAGE D-2 6805 INSTRUCTION SET D.3 6805 INSTRUCTION SET The following tables list all 6805 mnemonics recognized by the AS6805 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by AS6805: #data immediate data byte or word data *dir direct page addressing (see .setdp directive) 0 <= dir <= 255 (the value of dir must be defined within the current assembly) ,x register indirect addressing zero offset offset,x register indirect addressing 0 <= offset <= 255 --- byte mode 256 <= offset <= 65535 --- word mode (an externally defined offset uses the word mode) ext extended addressing label branch label The terms data, dir, offset, and ext may all be expressions. The terms dir and label are not allowed to be an external refer- ence. Note that not all addressing modes are valid with every in- struction, refer to the 6805 technical data for valid modes. D.3.1 Control Instructions clc cli nop rsp rti rts sec sei stop swi tax txa wait AS6805 ASSEMBLER PAGE D-3 6805 INSTRUCTION SET D.3.2 Bit Manipulation Instructions brset #data,*dir,label brclr #data,*dir,label bset #data,*dir bclr #data,*dir D.3.3 Branch Instructions bra label brn label bhi label bls label bcc label bcs label bne label beq label bhcc label bhcs label bpl label bmi label bmc label bms label bil label bih label bsr label AS6805 ASSEMBLER PAGE D-4 6805 INSTRUCTION SET D.3.4 Read-Modify-Write Instructions nega negx neg [] coma comx com [] lsra lsrx lsr [] rora rorx ror [] asra asrx asr [] lsla lslx lsl [] rola rolx rol [] deca decx dec [] inca incx inc [] tsta tstx tst [] clra clrx clr [] D.3.5 Register\Memory Instructions sub [] cmp [] sbc [] cpx [] and [] bit [] lda [] sta [] eor [] adc [] ora [] add [] ldx [] stx [] AS6805 ASSEMBLER PAGE D-5 6805 INSTRUCTION SET D.3.6 Jump and Jump to Subroutine Instructions jmp [] jsr [] APPENDIX E AS6809 ASSEMBLER E.1 .setdp DIRECTIVE Format: .setdp base [,area] The .setdp directive informs the assembler the base address of the direct page region (the low-order 8-bits of the base address are cleared) and specifies the direct page area. If the op- tional area name is left blank, then the current area is defined as containing the direct page. If a .setdp directive is not is- sued the assembler defaults the direct page to the area "_CODE". The .setdp directive is required when using the relocation features so that the direct page space may be positioned properly at link time. The assembler verifies that any variable referenced as a direct variable is located in this area and has a value from 0 to 255. It is the programmers responsibility to load the dp register with the correct page segment. E.2 6809 REGISTER SET The following is a list of the 6809 registers used by AS6809: a,b - 8-bit accumulators d - 16-bit accumulator x,y - index registers s,u - stack pointers pc - program counter cc - condition code dp - direct page AS6809 ASSEMBLER PAGE E-2 6809 INSTRUCTION SET E.3 6809 INSTRUCTION SET The following tables list all 6809 mnemonics recognized by the AS6809 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by AS6809: #data immediate data byte or word data *dir direct page addressing (see .setdp directive) 0 <= dir <= 255 (the value of dir must be defined within the current assembly) label branch label r,r1,r2 registers cc,a,b,d,dp,x,y,s,u,pc ,-x ,--x register indexed autodecrement ,x+ ,x++ register indexed autoincrement ,x register indexed addressing zero offset offset,x register indexed addressing -16 <= offset <= 15 --- 5-bit -128 <= offset <= -17 --- 8-bit 16 <= offset <= 127 --- 8-bit -32768 <= offset <= -129 --- 16-bit 128 <= offset <= 32767 --- 16-bit (external definition of offset uses 16-bit mode) a,x accumulator offset indexed addressing ext extended addressing ext,pc pc addressing ( pc <- pc + ext ) ext,pcr pc relative addressing [,--x] register indexed indirect autodecrement [,x++] register indexed indirect AS6809 ASSEMBLER PAGE E-3 6809 INSTRUCTION SET autoincrement [,x] register indexed indirect addressing zero offset [offset,x] register indexed indirect addressing -128 <= offset <= 127 --- 8-bit -32768 <= offset <= -129 --- 16-bit 128 <= offset <= 32767 --- 16-bit (external definition of offset uses 16-bit mode) [a,x] accumulator offset indexed indirect addressing [ext] extended indirect addressing [ext,pc] pc indirect addressing ( [pc <- pc + ext] ) [ext,pcr] pc relative indirect addressing The terms data, dir, label, offset, and ext may all be expres- sions. The terms dir and a short label are not allowed to be an external reference. Note that not all addressing modes are valid with every in- struction, refer to the 6809 technical data for valid modes. AS6809 ASSEMBLER PAGE E-4 6809 INSTRUCTION SET E.3.1 Inherent Instructions abx daa mul nop rti rts sex swi swi1 swi2 swi3 sync E.3.2 Short Branch Instructions bcc label bcs label beq label bge label bgt label bhi label bhis label bhs label ble label blo label blos label bls label blt label bmi label bne label bpl label bra label brn label bvc label bvs label bsr label E.3.3 Long Branch Instructions lbcc label lbcs label lbeq label lbge label lbgt label lbhi label lbhis label lbhs label lble label lblo label lblos label lbls label lblt label lbmi label lbne label lbpl label lbra label lbrn label lbvc label lbvs label lbsr label AS6809 ASSEMBLER PAGE E-5 6809 INSTRUCTION SET E.3.4 Single Operand Instructions asla aslb asl [] asra asrb asr [] clra clrb clr [] coma comb com [] deca decb dec [] inca incb inc [] lsla lslb lsl [] lsra lsrb lsr [] nega negb neg [] rola rolb rol [] rora rorb ror [] tsta tstb tst [] AS6809 ASSEMBLER PAGE E-6 6809 INSTRUCTION SET E.3.5 Double Operand Instructions adca [] adcb [] adda [] addb [] anda [] andb [] bita [] bitb [] cmpa [] cmpb [] eora [] eorb [] lda [] ldb [] ora [] orb [] sbca [] sbcb [] sta [] stb [] suba [] subb [] E.3.6 D-register Instructions addd [] subd [] cmpd [] ldd [] std [] E.3.7 Index/Stack Register Instructions cmps [] cmpu [] cmpx [] cmpy [] lds [] ldu [] ldx [] ldy [] leas [] leau [] leax [] leay [] sts [] stu [] stx [] sty [] pshs r pshu r puls r pulu r AS6809 ASSEMBLER PAGE E-7 6809 INSTRUCTION SET E.3.8 Jump and Jump to Subroutine Instructions jmp [] jsr [] E.3.9 Register - Register Instructions exg r1,r2 tfr r1,r2 E.3.10 Condition Code Register Instructions andcc #data orcc #data cwai #data E.3.11 6800 Compatibility Instructions aba cba clc cli clv des dex ins inx ldaa [] ldab [] oraa [] orab [] psha pshb pula pulb sba sec sei sev staa [] stab [] tab tap tba tpa tsx txs wai APPENDIX F AS6811 ASSEMBLER F.1 .setdp DIRECTIVE Format: .setdp [area] The .setdp directive informs the assembler in which area the direct page is located. If the optional area name is left blank, then the current area is defined as containing the direct page. If a .setdp directive is not issued the assembler defaults the direct page to the area "_CODE". The .setdp direc- tive is required when using the relocation features so that the direct page space may be positioned properly at link time. The assembler verifies that any variable referenced as a direct variable is located in this area and has a value from 0 to 255. F.2 6811 REGISTER SET The following is a list of the 6811 registers used by AS6811: a,b - 8-bit accumulators d - 16-bit accumulator x,y - index registers AS6811 ASSEMBLER PAGE F-2 6811 INSTRUCTION SET F.3 6811 INSTRUCTION SET The following tables list all 6811 mnemonics recognized by the AS6811 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by AS6811: #data immediate data byte or word data *dir direct page addressing (see .setdp directive) 0 <= dir <= 255 (the value of dir must be defined within the current assembly) ,x register indirect addressing zero offset offset,x register indirect addressing 0 <= offset <= 255 (the value of offset must be defined within the current assembly) ext extended addressing label branch label The terms data, dir, offset, and ext may all be expressions. The terms dir, offset, and label are not allowed to be external references. Note that not all addressing modes are valid with every in- struction, refer to the 6811 technical data for valid modes. AS6811 ASSEMBLER PAGE F-3 6811 INSTRUCTION SET F.3.1 Inherent Instructions aba abx aby cba clc cli clv daa des dex dey fdiv idiv ins inx iny mul nop rti rts sba sec sei sev stop swi tab tap tba tpa tsx txs wai xgdx xgdy psha pshb psh a psh b pshx pshy psh x psh y pula pulb pul a pul b pulx puly pul x pul y F.3.2 Branch Instructions bra label brn label bhi label bls label bcc label bhs label bcs label blo label bne label beq label bvc label bvs label bpl label bmi label bge label blt label bgt label ble label bsr label AS6811 ASSEMBLER PAGE F-4 6811 INSTRUCTION SET F.3.3 Single Operand Instructions asla aslb asld asl a asl b asl d asl [] asra asrb asr a asr b asr [] clra clrb clr a clr b clr label coma comb com a com b com [] deca decb dec a dec b dec [] inca incb inc a inc b inc [] lsla lslb lsld lsl a lsl b lsl d lsl [] lsra lsrb lsrd lsr a lsr b lsr d lsr [] nega negb neg a neg b neg [] rola rolb rol a rol b rol [] rora rorb ror a ror b ror [] tsta tstb tst a tst b tst [] AS6811 ASSEMBLER PAGE F-5 6811 INSTRUCTION SET F.3.4 Double Operand Instructions adca [] adcb [] adc a [] adc b [] adda [] addb [] addd [] add a [] add b [] add d [] anda [] andb [] and a [] and b [] bita [] bitb [] bit a [] bit b [] cmpa [] cmpb [] cmp a [] cmp b [] eora [] eorb [] eor a [] eor b [] ldaa [] ldab [] lda a [] lda b [] oraa [] orab [] ora a [] ora b [] sbca [] sbcb [] sbc a [] sbc b [] staa [] stab [] sta a [] sta b [] suba [] subb [] subd [] sub a [] sub b [] sub d [] F.3.5 Bit Manupulation Instructions bclr [],#data bset [],#data brclr [],#data,label brset [],#data,label AS6811 ASSEMBLER PAGE F-6 6811 INSTRUCTION SET F.3.6 Jump and Jump to Subroutine Instructions jmp [] jsr [] F.3.7 Long Register Instructions cpx [] cpy [] ldd [] lds [] ldx [] ldy [] std [] sts [] stx [] sty [] APPENDIX G AS8085 ASSEMBLER G.1 8085 REGISTER SET The following is a list of the 8080/8085 registers used by AS8085: a,b,c,d,e,h,l - 8-bit accumulators m - memory through (hl) sp - stack pointer psw - status word G.2 8085 INSTRUCTION SET The following tables list all 8080/8085 mnemonics recognized by the AS8085 assembler. The following list specifies the format for each addressing mode supported by AS8085: #data immediate data byte or word data r,r1,r2 register or register pair psw,a,b,c,d,e,h,l bc,de,hl,sp,pc m memory address using (hl) addr direct memory addressing label call or jump label The terms data, m, addr, and label may be expressions. Note that not all addressing modes are valid with every in- struction, refer to the 8080/8085 technical data for valid modes. AS8085 ASSEMBLER PAGE G-2 8085 INSTRUCTION SET G.2.1 Inherent Instructions cma cmc daa di ei hlt nop pchl ral rar ret rim rrc rlc sim sphl stc xchg xthl G.2.2 Register/Memory/Immediate Instructions adc r adc m aci #data add r add m adi #data ana r ana m ani #data cmp r cmp m cpi #data ora r ora m ori #data sbb r sbb m sbi #data sub r sub m sui #data xra r xra m xri #data G.2.3 Call and Return Instructions cc label rc cm label rm cnc label rnc cnz label rnz cp label rp cpe label rpe cpo label rpo cz label rz call label G.2.4 Jump Instructions jc label jm label jnc label jnz label jp label jpe label jpo label jz label jmp label AS8085 ASSEMBLER PAGE G-3 8085 INSTRUCTION SET G.2.5 Input/Output/Reset Instructions in data out data rst data G.2.6 Move Instructions mov r1,r2 mov r,m mov m,r mvi r,#data mvi m,#data G.2.7 Other Instructions dcr r dcr m inr r inr m dad r dcx r inx r ldax r pop r push r stax r lda addr lhld addr shld addr sta addr lxi r,#data APPENDIX H ASZ80 ASSEMBLER H.1 .hd64 DIRECTIVE Format: .hd64 The .hd64 directive enables processing of the HD64180 specific mnemonics not included in the Z80 instruction set. HD64180 mnemonics encountered without the .hd64 directive will be flagged with an 'o' error. H.2 Z80 REGISTER SET AND CONDITIONS The following is a complete list of register designations and condition mnemonics: byte registers - a,b,c,d,e,h,l,i,r register pairs - af,af',bc,de,hl word registers - pc,sp,ix,iy C - carry bit set M - sign bit set NC - carry bit clear NZ - zero bit clear P - sign bit clear PE - parity even PO - parity odd Z - zero bit set ASZ80 ASSEMBLER PAGE H-2 Z80 INSTRUCTION SET H.3 Z80 INSTRUCTION SET The following tables list all Z80/HD64180 mnemonics recog- nized by the ASZ80 assembler. The designation [] refers to a required addressing mode argument. The following list specifies the format for each addressing mode supported by ASZ80: #data immediate data byte or word data n byte value rg a byte register a,b,c,d,e,h,l rp a register pair bc,de,hl (hl) implied addressing or register indirect addressing (label) direct addressing offset(ix) indexed addressing with an offset label call/jmp/jr label The terms data, dir, offset, and ext may all be expressions. The terms dir and offset are not allowed to be external refer- ences. Note that not all addressing modes are valid with every in- struction, refer to the Z80/HD64180 technical data for valid modes. ASZ80 ASSEMBLER PAGE H-3 Z80 INSTRUCTION SET H.3.1 Inherent Instructions ccf cpd cpdr cpi cpir cpl daa di ei exx halt neg nop reti retn rla rlca rld rra rrca rrd scf H.3.2 Implicit Operand Instructions adc a,[] adc [] add a,[] add [] and a,[] and [] cp a,[] cp [] dec a,[] dec [] inc a,[] inc [] or a,[] or [] rl a,[] rl [] rlc a,[] rlc [] rr a,[] rr [] rrc a,[] rrc [] sbc a,[] sbc [] sla a,[] sla [] sra a,[] sra [] srl a,[] srl [] sub a,[] sub [] xor a,[] xor [] ASZ80 ASSEMBLER PAGE H-4 Z80 INSTRUCTION SET H.3.3 Load Instruction ld rg,[] ld [],rg ld (bc),a ld a,(bc) ld (de),a ld a,(de) ld (label),a ld a,(label) ld (label),rp ld rp,(label) ld i,a ld r,a ld a,i ld a,r ld sp,hl ld sp,ix ld sp,iy ld rp,#data ldd lddr ldi ldir H.3.4 Call/Return Instructions call C,label ret C call M,label ret M call NC,label ret NC call NZ,label ret NZ call P,label ret P call PE,label ret PE call PO,label ret PO call Z,label ret Z call label ret H.3.5 Jump and Jump to Subroutine Instructions jp C,label jp M,label jp NC,label jp NZ,label jp P,label jp PE,label jp PO,label jp Z,label jp (hl) jp (ix) jp (iy) jp label djnz label jr C,label jr NC,label jr NZ,label jr Z,label jr label ASZ80 ASSEMBLER PAGE H-5 Z80 INSTRUCTION SET H.3.6 Bit Manipulation Instructions bit n,[] res n,[] set n,[] H.3.7 Interrupt Mode and Reset Instructions im n im n im n rst n H.3.8 Input and Output Instructions in a,(n) in rg,(c) ind indr ini inir out (n),a out (c),rg outd otdr outi otir H.3.9 Register Pair Instructions add hl,rp add ix,rp add iy,rp adc hl,rp sbc hl,rp ex (sp),hl ex (sp),ix ex (sp),iy ex de,hl ex af,af' push rp pop rp ASZ80 ASSEMBLER PAGE H-6 Z80 INSTRUCTION SET H.3.10 HD64180 Specific Instructions in0 rg,(n) out0 (n),rg otdm otdmr otim otimr mlt bc mlt de mlt hl mlt sp slp tst a tstio #data