An assembler supports directives
to define data, to organise segments to control procedure, to define macros
. It consists of two types of statements: instructions and directives. The instructions are translated to the machine code by the assembler whereas directives are not translated to the machine codes.
What are assembler directives?
Directives are instructions used by the assembler to help automate the assembly process and to improve program readability. Examples of common assembler directives are
ORG (origin), EQU (equate), and DS. B (define space for a byte)
. … The assembler directives listed below are the most common ones used for Code Warrior.
What are assembler directives explain 4 assembler directives in detail?
Assembler directives
supply data to the program and control the assembly process
. Assembler directives enable you to do the following: Assemble code and data into specified sections. Reserve space in memory for uninitialized variables. Control the appearance of listings.
What is the meaning of DQ assembler directive in 8086?
The DQ directive is used
to tell the assembler to declare a variable 4 words in length or to reserve 4 words of storage in memory
.
What are the assembler directives of 8086?
An assembler supports directives
to define data, to organise segments to control procedure, to define macros
. It consists of two types of statements: instructions and directives. The instructions are translated to the machine code by the assembler whereas directives are not translated to the machine codes.
What is difference between macro and procedure?
A macro is used for a small number of instructions; mostly, less than ten instructions, while
a procedure is used for a large number of instructions; mostly, higher than ten instructions
. Hence, this is the main difference between macro and procedure.
What are the types of assemblers?
- 6502 assemblers.
- 680×0 assemblers.
- ARM assemblers.
- IBM mainframe assemblers.
- POWER, PowerPC, and Power ISA assemblers.
- x86 assemblers.
- x86-64 assemblers.
- Z80 assemblers.
What is difference between assembler directives and instructions?
Answer: Assembler instruction generates machine code, thus contributes towards the size of the program .
Assembler directive does not create any machine code
,thus does not contribute to program size.It directs the assembler to perform certain actions during assembly phase.
What are the advanced assembler directives?
Assembler directives are
instructions that direct the assembler to do something
. Assigns a value to a symbol (same as =) Sets the current origin to a new value. … For example, ORG 0100h tells the assembler to assemble all subsequent code starting at address 0100h.
What is the purpose of the origin directive?
The origin directive tells
the assembler where to load instructions and data into memory
. It changes the program counter to the value specified by the expression in the operand field. Subsequent statements are assembled into memory locations starting with the new program/location counter value.
Why are assembler directives required?
The assembler directives control organization of the program and
provide necessary information to the assembler to understand assembly language programs to generate machine codes
. They indicate how an operand or a section of program is to be processed by the assembler.
What are assembler directives list any four assembler directives and its usage?
Category Directives | Compiler-Use-Only Directives .bgnb .endb .file .gjsrlive .gjsrsaved .lab .livereg .loc .option .ugen .vreg | Location Control Directives .align .data .rdata .sdata .space .text | Symbol Declaration Directives .extern .globl .struct symbolic equate .weakext |
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What is the function of EQU assembler directive?
In assembly code, the assembler directive EQU is
used to assign a label to a number
, which can be a literal, a file register number or an individual register bit.
Which assembler directive is used to address 32 bit?
equ = define symbolic constants. DB = define byte size variables. DW = define word size (16 bits) variables.
DD =
define double word size (32 bits) variables.
Which directive ends a procedure?
The ENDP directive
marks the end of the main procedure.
Which assembler directive is used in FAR procedure?
The
PROC directive
is used to identify the start of a procedure. The PROC directive follows a name you give the procedure. After the PROC directive, the term near or the term far is used to specify the type of the procedure.