What do you mean by assembler directives

RAM is the memory available for the operating system, programs and processes to use when the computer is running. ROM is the memory that comes with your computer that is pre-written to hold the instructions for booting-up the computer.

RAM requires a flow of electricity to retain data e. Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Cover Letter What is assembler directive explain assembler directive with proper example? Cover Letter. Assembler directives- These are the statements that direct the assembler to do something. As the name says, it directs the assembler to do a task.

The specialty of these statements is that they are effective only during the assembly of a program but they do not generate any code that is machine executable. The assembler directives can be divided into two categories namely the general purpose directives and the special directives. They are classified into the following categories based on the function performed by them- Simplified segment directives Data allocation directives Segment directives Macros related directives Code label directives Scope directives Listing control directives Miscellaneous directives.

CODE- This assembler directive indicates the beginning of the code segment. Its format is as follows:. CODE [name] The name in this format is optional. We have no stock, but DigiKey has a few items.. Assembler directives are instructions that direct the assembler to do something Directives do many things; some tell the assembler to set aside space for variables, others tell the assembler to include additional source files, and others establish the start address for your program.

The directives available are shown below:. ORG Sets the current origin to a new value. This is used to set the program or register address during assembly. Note that while directives are not case sensitive, labels and symbols ARE case-sensitive: 'Buf1:'! A comment line contains a semicolon followed by text. A comment can also be placed at the end of a source line. Comments are included in the assembly listing, but are not significant to the assembler.

Labels are required on assembler directives that define the value of a symbol for instance, EQU. For these directives, labels are assigned the value corresponding to the expression in the operand field. Note the labels MUST begin in column zero; there can't be any white space before a label but note that some directives like ORG noted below do require whitespace in the leading column. Double quotes are only allowed within strings delimited by single quotes.

Single quotes are only allowed within strings delimited by double quotes. Common Code Warrior Directives. If a label does not precede a directive, you MUST indent or put a space before the directives noted below. Use the case that gives the best readability. In contrast, remember that the case of labels and symbols IS case-sensitive: 'Buf1:'! We must use this directive for absolute assembly files generated in this course. B - Define constant in memory of length one byte.

This assigns a memory address M to a constant and initializes the constant.