Equ in 8086 The syntax for equ on the HPPA is `symbol. SCREEN_WIDTH equ 80. Given below are some Examples of the String manipulation instructions in 8086 microprocessor. To define numeric or string constants. Syntax: ORG note: may be a unsigned absolute value or any symbol or symbol + . The symbol is a label that must appear in the EQU 指令. ), set segment and symbol properties (ASSUME, SEGMENT, EXTRN, PUBLIC), organize code (GROUP, INCLUDE, ORG), and perform other tasks like equating symbols. Direttive di Segmento Apr 18, 2022 · 8086伪指令（汇编语言程序格式） 汇编语言程序中的语句可以由指令、伪指令和宏指令组成。 每一条 指令 都对应一种CPU操作。 伪指令 又称为伪操作，它是在对源程序汇编期间由汇编程序处理的操作，它们可以完成如处理器选择、定义程序模式、定义数据、分配 1. CONSTANT_NAME EQU expression For example, TOTAL_STUDENTS equ 50 May 24, 2017 · The EQU directive is used to give name to some value or symbol. The EQU directive is used for defining constants. Data Organization: DB, DW, and EQU Representing data types in assembly source files requires appropriate assembler directives. msg db 'Hello, world!',0xa ;our dear string len equ 13 ;length of our dear string Oct 31, 2016 · 我在汇编程序（8086）中制作清晰的EQU指令时遇到了麻烦。 abc EQU xyz 当在xyz的代码中找到时，无论xyz代表什么，值等，EQU是否真的交换了abc？ 我可以写吗？ varA EQU [bp+4] mov ax, varA 还有一个问题是EQU全局访问，即我可以在程序中定义EQU，并在程序中使用它吗？ Aug 31, 2016 · . 8. equ JELLO, 0x12345678 ldr r0,JELLO . Assembler Directives of 8086. The 8086 instructions are categorized into the following main types. EQU 伪指令把一个符号名称与一个整数表达式或一个任意文本连接起来，它有 3 种格式： name EQU expression name EQU symbol name EQU <text> 第一种格式中，expression 必须是一个有效整数表达式。第二种格式中，symbol 是一个已存在的符号名称，已经用 = 或 EQU 定义过了。 Nov 19, 2016 · 定义静态符号 虽然数据段主要用于定义变量数据，但是也可以在这里声明静态数据符号。 . data equ, assume, and end. It provides information to the assembler regarding the name of the program or data segment for that particular segment. mov ecx, TOTAL_STUDENTS cmp eax, TOTAL_STUDENTS The operand of an EQU statement can be an expression − We have already used the EQU directive in previous chapters. e. So, for example, message db 'hello, world' msglen equ $-message c1 equ 21h d1 equ 25h e1 equ 29h f1 equ 42h g1 equ 49h a1 equ 55h And then i have to somehow use value read from file, for example c1 (this would be 6331 in hexadecimal i think), and instruction EQU to somehow get the value, like 21h. set symbol, expression. set /. LENGTH equ 20 WIDTH equ 10 AREA equ length * width The EQU instruction assigns absolute or relocatable values to symbols. 6. ldr r0,0x12345678 so. While the documentation is confusing, the statement "The name cannot be redefined later" only applies to the first form of EQU "name EQU expression", whereas the second form of EQU "name EQU <text>" is annotated with "The name can be assigned a different text later. stack 4096 ExitProcess PROTO, dwExitCode:DWORD . x86assemblycode. 4. A pseudo-opcode is a message to the assembler, just like an assembler directive, how-ever a pseudo-opcode will emit object code bytes. data ;EQU directive defines a symbol by either an integer or text ;EQU directive makes the symbolic constant so it can't be redefined. Data Copy / Transfer Instructions. We will particularly discuss three directives −. Examples of pseudo-opcodes include byte, word dword, qword, and tbyte Mar 5, 2024 · Examples of String manipulation instructions in 8086 microprocessor. EQU指令用于定义常量。 EQU指令的语法如下 −. Clearly differentiate between short, near and far jump. EQU %assign %define; The EQU Directive. May 24, 2017 · The EQU directive is used to give name to some value or symbol. The . The action of EQU is to define the given label name to the value of its (only) operand. Verify all content and data in the device’s PDF documentation found on the device product page. The value assigned by the EQU directive can be recalled in subsequent source lines by referring to its assigned name. equ directives equate a constant value to a . EQU伪指令可以定义非整数，语法为： name EQU expression name EQU symbol name EQU <text> EQU伪指令是通过文本替换的方式完成，定义非整数可以用 name EQU <text>的形式，当汇编器在程序后面遇到name时会将它替换成<text>里的内容。请注意，EQU伪指令不可被重定义。 Machine Language Formats 8086 Addressing Modes 8086/8088 Instruction Set-1 8086/8088 Instruction Set-2 8086/8088 Instruction Set-3 Assembler Directives Special Architectural Features & Related Programming The EQU expression cannot contain any external symbol. set'; see section . g. This directive sets the value of symbol to expression. It describes directives that define data types (DB, DW, DD, etc. The directives allocate data and format x86 little-endian values. exe yellow_and_green equ 0000_0110b Equate directive (EQU) equates a numeric, ASCII, or label to another label. 2. equ symbol, expression. . Flag Manipulation Instructions. These assembler directives are specifically used by 8086: ASSUME: Shows the segment name to the assembler. " 1、equ 指令用于将一个数值或寄存器名赋给一个指定的符号名。格式： 符号名 equ 表达式 符号名 equ 寄存器名表达式必须是一个简单再定位表达式。用 equ 指令赋值以后的字符名，可以用作数据地址、代码地址、位地址或者直接当做一个立即数使用。 The . If you weren't using equ, and for some reason needed to change the width of your UI, you'd need to go through all your code and update every instance of the number 80, etc. Loops are used to iterate a set of statements for a specific number of times. equ LINUX_SYS_CALL, 0x80 经过设置之后，数据符号值是不能在 程序中改动的。 . May 17, 2016 · Dichiarazione di una costante: direttiva EQU Sintassi di EQU: <identificatore> EQU <valore> Es: _AT_ EQU ‘@’ Es: NUM_MESI EQU 12. equ 命令可以出现 The document discusses various assembler directives used in assembly language programming. SCREEN_HEIGHT equ 40. %define. 虽然equ和data具有相似的作用，但是两者直接具有以下区别：equ须先定义后使用，而data可无须如此。其次，equ可把汇编符号赋给一个字符名称，而data伪指令则不能。data可用于表达式，而equ不行。 参考资料来源：百度百科-equ（指令equ解释） INSTRUCTION SET OF 8086. - Being active during assembling and no machine language code is generated. I am taking a class in x86 assembly language and it's starting to move rather fast. We can also write. equ和“=”的区别： 使用EQU伪指令定义的符号名不能与其他符号名重名，符号名必须唯一，且不能被重新定义，而使用等号伪指令定义的符号名可以重名，可以被重新定义、重新赋值。 Nov 29, 2010 · equ编辑本段表达式赋值操作符EQU 有时候程序中多次出现同一个表达式，为方便起见，可以用赋值伪操作给表达式赋予一个名字。 其格式如下： Expression_name EQU Expression 此后程序中凡需要用到该表达式指出，就可以用表达式名来代替了。 The online versions of the documents are provided as a courtesy. Jun 11, 2020 · EQU also explicitly states that a text value can be changed after declaration. %define constant_name value Loops. 5. not only are these directives but directives as well as assembly language is very specific to the assembler, the program that is being used, no reason to assume that any two 8086 assemblers use the same assembly language or directives, so you need to be a bit more specific next time – We would like to show you a description here but the site won’t allow us. EQU EQU. Defining variables in asm. Jun 3, 2018 · Visithttps://www. The value can be in the range 0 through 65535 and it can be another Equate declared anywhere above or below. STACK 100. Oct 31, 2016 · I'm having trouble just making clear EQU directive in assembler (8086). equ, assume, and end. Use it to: Assign single absolute values to symbols. mov ecx, TOTAL_STUDENTS cmp eax, TOTAL_STUDENTS EQU 语句的操作数可以是表达式 −. %assign constant_name value 3. s:2: Error: internal_relocation (type: OFFSET_IMM) not fixed up now if we want the VALUE in r0, then it is a syntax problem. equ is a define like substitution. - Details on assembler directives like data declaration directives (DB, DW, DD), origin directives (ORG), end directives (END, ENDP, ENDS), and equate directives (EQU). To define numeric constants. Jan 14, 2017 · . s: Assembler messages: so. 0. So it seems like equ is used to define constants, but is = the same thing? If I had some code: Assembler Directives of 8086. The syntax of the EQU directive is as follows −. - Different types of operators are: 1) Arithmetic: + , - , * , / 2) Logical : AND, OR, XOR, NOT Jan 6, 2009 · 在学校学习了8086与汇编后，假期有兴趣看了看于渊的《自己动手写操作系统》，发现了许多“有趣”的不同。记录一下，供大家参考纠正错误。 记录一下，供大家参考纠正错误。 Discuss the different types of 8086 unconditional jump instructions with an example for each type. To define numeric constants; CONSTANT_NAME EQU regular-exp or value 2. They are messages to the assembler, nothing else. L’assembler sostituisce il nome di una costante con il suo valore Es: MOV AL,_AT_ diventa MOV AL,40h <valore> può essere: un valore numerico; una stringa di caratteri tra apici Variables - 8086 assembler tutorial for beginners. The EQU instruction assigns absolute or relocatable values to symbols. equ 命令用于把常量值设置为可以在文本段中使用的符号 如： . String Instructions. Whenever this name is used as a symbol, it is replaced. Assign the values of previously defined symbols or expressions to new symbols, thus letting you use different mnemonics for different purposes. equ factor, 3 . 8086 assembler tutorial for beginners (part 3) name EQU < any expression > For example: k EQU 5 MOV AX, k May 29, 2011 · 文章浏览阅读3. CODE START: MOV DX,CONTROL Jul 28, 2017 · I am learning assembly using the following hello world program. Branch Instructions. Equates make a program clearer and simplify debugging . You may set the same symbol any number of times in assembly. (10 Marks) List the conditional jump instructions that are used for signed numbers. Loop Instructions. section . Microprocessors Chapter 3 : Programming with 8086 Microprocessor Operators in 8086 - Operator can be applied in the operand which uses the immediate data/address. There is one thing that the book keeps doing without mentioning how it works, and that is using the equ and = operators when defining data. Sep 9, 2008 · The first EQU statement assigns a complexly relocatable expression (A1+B1) to X. 1. Does EQU literally swaps abc when found in code with xyz, whatever xyz represents, value etc? i. Key directives covered include those for declaring variables of specific sizes The . The EQU directive is used to equate a name with an expression, symbolic address, or number. com/for more information and x86 assembly source code. The EQU Directive. During the evaluation of the expression in the second EQU statement, X is replaced by its defining relocatable expression (A1+B1), and the assembler evaluates the resulting expression (A1+B1-A2-B2) and assigns an absolute value to Y, because the relocatable terms EQU - This EQU directive is used to give a name to some value or to a symbol. Therefore, $-msg gives the length of the string. can I define EQU out of procedure, and in procedure to use it? Depends on the actual assembler you use. . Googling for the keywords RMK, CPY and EQU doesn't turn up anything so it appears to be a very obscure language. Can i write? And one more question is EQU globally accessed, i. Jan 17, 2008 · ; STAIRCASE WAVEFORM GENERATOR with 8086 using 8255 MODEL SMALL. set and . The symbol is a label that must appear in the COLUMNS EQU 80 ROWS EQU 25 E‟ possibile anche creare degli alias, cioè simboli che rappresentano con altri nomi simboli già definiti in precedenza. COLONNE EQU COLUMNS RIGHE EQU ROWS SCREEN EQU COLONNE * RIGHE In alternativa ad EQU per definire delle costanti è anche possibile utilizzare l‟operatore di assegnazione = . CONSTANT_NAME EQU expression For example, TOTAL_STUDENTS equ 50 You can then use this constant value in your code, like −. Feb 15, 2018 · It contains: - An introduction to 8086 assembly language programming and serial monitor operation on an 8086 trainer kit. Example of REP with MOVSB Instruction MOV AX, 7000H Assign source segment address to AX MOV DS, AX Load source segment address into DS Feb 25, 2016 · It looks like some mainframe oriented programming or job control language, the kind where things had to be in certain columns. Dec 23, 2011 · 汇编语言中，count equ $-DA 中 $-DA是定义一个变量count并赋值$-DA，$是当前地址，DA是这条语句之前定义的变量地址，$-DA用于统计当前地址与DA这个地址间有多少字节。 Feb 12, 2012 · Traffic light programming in assembly for 8086 ; Traffic ligts test 2 for; c:\emu8086\devices\Traffic_Lights. R12 EQU 12 The . e. How to write constants in the data segment in x86 assembly. Shift and Rotate Instructions. msg db 'Hello, world!',0xa ;our dear string len equ $ - msg ;length of our dear string $ points to the byte after the last character of the string variable msg. equ. May 1, 2010 · 利用EQU伪指令，就可以避免这些问题的发生。 格式： EQU 该伪指令的含义是为EQU后面的起一个叫做的名字。这样一来，程序中凡是需要用到该表达式的地方，就都可以用这个名字代替了。这里，可以是任何有效的数据_equ $ Apr 19, 2020 · EQU伪指令. %assign. 2w次，点赞16次，收藏62次。本文详细解析了c语言中count指令的几种不同使用方式及其内存分配特性，包括equ、dw、db指令的区别，以及在代码段中如何合理使用这些指令以优化内存使用效率。 I suspect he simply means that equ can be used for giving helpful names to pieces of data. If you set a global symbol, the value stored in the object file is the last value equated to it. (8M) Explain conditional and unconditional jump instructions in 8086 MP with example of each. EQU directive in GAS assembly. equ expression'. word 0x12345678 No change, if I do this. DATA CONTROL EQU 0FFC6H ; Control port address for 8255 PORTA EQU 0FFC0H ; Port A address for 8255 PORTB EQU 0FFC2H ; Port B address for 8255 PORTC EQU 0FFC4H ; Port C address for 8255. text global _start ;must be declared for linker (ld) _start: ;tells linker entry point mov edx,len ;message length mov ecx,msg ;message to write mov ebx,1 ;file descriptor (stdout) mov eax,4 ;system call number (sys_write) int 0x80 ;call kernel mov eax,1 ;system call number (sys_exit) int 0x80 ;call kernel section . The symbol can then be used in place of a value in assembly source. 386 . This definition is absolute, and cannot change later. If the word starts at an odd address, the microprocessor must do two read cycles to get 2 bytes of the word. extern. 3. CONSTANT_NAME EQU expression 例如， TOTAL_STUDENTS equ 50 然后您可以在代码中使用这个常量值，例如 −. The 8086 can read a word from memory in one bus cycle if the word is at an even address. 0以上都常用这个伪指令。它不是80x86的指令集合。 它不是80X86的指令集合。 而汇编在第一次扫描时只扫描了指令，而将伪指令中的东西作为“动态内容”作了标记而已。 May 18, 2017 · assemble then disassemble and see what each does. equ symbol. Each time the assembler finds the name in the program, it will replace the name with the value or symbol you given to that name. In the first cycle it will read the LSB and in the second it will read MSB. 7. This allows you to equate meaningful names with constants and other values. Oct 31, 2016 · I'm having trouble just making clear EQU directive in assembler (8086). Examples of pseudo-opcodes include byte, word dword, qword, and tbyte During the assemble time ORG directive resets the MLC (memory location counter) to the address specified in the ORG directive. equ JELLO, 0x22 ldr r0,hello nop nop nop hello: . Arithmetic and Logical Instructions. equ directives are identical and can be used interchangeably. mov ECX,n L1: ;<loop body> loop L1 伪指令不是真正的指令，并没有与之对应的的机器码，不会被执行。伪指令所起的作用主要是对汇编过程进行控制。常见的伪指令如下所示：目录（1）org———汇编起始指令（2）end——汇编结束命令（3）equ— equ不是指令集，而是 伪指令 ，一般我们常使用的masm5. These mnemonics are not valid 80x86 instructions. See here for more discussion, especially on how a frame pointer was needed on the 16-bit 8086. EQU defines a symbol to a given constant value: when EQU is used, the source line must contain a label. Apr 28, 2012 · EQU defines a symbol to a given constant value: when EQU is used, the source line must contain a label. Sep 16, 2020 · Assembly 8086 EQU directive. equ symbol, expression directive sets the value of symbol to expression. Each time the assembler finds the given names in the program, it will replace the name with the value or a symbol. EQU (Equate) is used to attach a value to a variable Examples: 7 END EVEN EQU PROC FAR NEAR ENDP SHORT MACRO ENDM ORG 1000H Informs the assembler that the statements following ORG 1000H should be stored in memory starting with effective address1000 H LOOP EQU 10FEH ValueofvariableLOOPis10FE H _SDATA SEGMENT ORG 1200H A DB 4CH EVEN B DW 1052H Jan 24, 2013 · 文章浏览阅读7k次，点赞4次，收藏6次。不同点：1、使用equ伪指令定义的符号名不能与其它符号名重名,符号名必须唯一,且不能被重新定义;而使用等号伪指令"="定义的符号名可以重名,可以被重新定义,可被重新赋值。 Oct 31, 2016 · I'm having trouble just making clear EQU directive in assembler (8086). extern is accepted in the source program--for compatibility with other assemblers--but it is ignored. We might do something, such as the following, which makes the symbol R12 to be equal to 12, and replaced by that value when the assembler is run. Ex: CONTROL_WORD EQU 11001001 ; replacement MOVAX, CONTROL_WORD ;assignmeent Each time the assembler finds the given name in the program, it will replace the name with the value or symbol we equated with that name. It is synonymous with `. model flat,stdcall . SET Directive : Jan 1, 2022 · Historically, the 16-bit 8086 did not support the stack pointer as a base register in displacement addressing, so a frame pointer was required for that. And I honestly have no idea where to look for any clue on how to do this. For example, The following EQU directive enters the name ONES into the symbol table and assigns the binary value 11111111 to it: ONES EQU FFH. kzqrm wytx gibrav xplnho gtkzf bkywycp nojaiutdh hxzutc raipj chxyp eeuag mbrnnc fypo bjubcvx smlzbo