What are the five assembler directives
5 Assembler Directives
- Assemble code and data into specified sections.
- Reserve space in memory for uninitialized variables.
- Control the appearance of listings.
- Initialize memory.
- Assemble conditional blocks.
- Define global variables.
- Specify libraries from which the assembler can obtain macros.
What are the types of assemblers
On the basis of a number of phases used to convert to machine code, assemblers have two types:
- One-Pass Assembler. These assemblers perform the whole conversion of assembly code to machine code in one go.
- Multi-Pass/Two-Pass Assembler.
What are assembler directives in 8051
The following are the widely used 8051 assembler directives.
ORG (origin) The ORG directive is used to indicate the starting address. It can be used only when the program counter needs to be changed. The number that comes after ORG can be either in hex or in decimal. Eg: ORG 0000H ;Set PC to 0000.
What do you mean by an assembler
An assembler is a program that takes basic computer instructions and converts them into a pattern of bits that the computer's processor can use to perform its basic operations. Some people call these instructions assembler language and others use the term assembly language.
How many types of assemblers are there
There are two types of assemblers based on how many passes through the source are needed (how many times the assembler reads the source) to produce the object file. One-pass assemblers go through the source code once.
What are directives in programming
In computer programming, a directive or pragma (from "pragmatic") is a language construct that specifies how a compiler (or other translator) should process its input. Directives are not part of the grammar of a programming language, and may vary from compiler to compiler.
What is difference between assembler directives and instructions
An instruction is directly translated to something the CPU can execute. A directive is something the assembler can interpret, and tells something about the way the instructions are to be assembled. Directives are never something the CPU will see.
What is assembler directive in MIPS
Directives are instructions to the assembler, specifying an action to be taken during the assembly process. One important use of directives is declaring or reserving memory variables. In addition, directives are used to break up the program into sections.
What are DC and DS statements
The two primary data definition statements are the DS directive and the DC directive. The DS directive allocates space for a label; the DC allocates space and assigns an initial value. These declaratives are statements that assign storage locations.
What is the use of origin assembler directive
Origin : The origin directive tells the assembler where to load instructions and data into memory. The 68000 reserves the first 1024 bytes of memory for exception vectors. Your programs will start at location 1024; that is, you should begin your program with ORG 1024 or ORG $400 (remember that 1024 = 40016).
What are arm directives
Alphabetical list of directives
|ALIGN||EXPORT or GLOBAL||MACRO and MEND|
|ARM or CODE32||EXPORTAS||MAP|
|AREA||EXTERN||MEND (see MACRO )|
What is the format for assembly language statement
An x86 assembly language program consists of one or more files containing statements. A statement consists of tokens separated by whitespace and terminated by either a newline character (ASCII 0x0A) or a semicolon (;) (ASCII 0x3B).
What are the types of statements in assembler
A typical assembly language consists of 3 types of instruction statements that are used to define program operations:
- Opcode mnemonics.
- Data definitions.
- Assembly directives.
What is assembler explain the different assembler directives with example
Initialize memory. Assemble conditional blocks. Define global variables. Specify libraries from which the assembler can obtain macros.
5.1 Directives Summary.
|Mnemonic and Syntax||Description||See|
|.byte value1[, , valuen]||Initializes one or more successive bytes in the current section||.byte topic|
Is end an assembler directive
The END directive informs the assembler that it has reached the end of a source file.
What is the use of 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. In BIN4, 'porta' and 'portb' are the port data registers (05 and 06) and 'timer' is the first spare register (0C), which will be used as a counter register.
What is EQU directive
The EQU directive gives a symbolic name to a numeric constant, a register-relative value or a PC-relative value.
What are assembler directives or pseudo instructions
Assembler directives are commands to the assembler in the form of pseudo-operations. Some directives cause the assembler to generate code or data, while others do not. The different types of assembler directives are: Section Control Directives.