After using this directive, every appearance of the label ³MAXIMUM´ in the program will be interpreted by the assembler as the number 99 (MAXIMUM = 99). The Appendix includes information on the and MCS instruction set, a summary of directives and controls, the differences between assembler versions. ASSUME Directive. -. The ASSUME directive is used to tell the assembler that the name of the logical segment should be used for a specified segment.

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The END directive is the last line of an program. A discussion of signed numbers is given in Chapter 6. Every assembler has some reserved words which must not be used as labels in the program.

There are several rules that names must follow. The number that comes after ORG can be either in hex or in decimal. In assembly language programming anything after the END directive is ignored by the assembler. These reserve words are the mnemonics for the instructions e. Directibes decimal, the “D” after the decimal number is optional, but using “B” [binary] and “H” [hexadecimal] is required. If the number is not followed by ‘H’, it is decimal and the assembler will convert it into hex.


Some assemblers use “. EQU is used to define a constant without occupying a memory location. The following Assembler directives are widely used in Assembly language programming.


DB is also used to allocate memory in assembelr chunks. The data type used by the can be positive or negative. Labels in Assembly Language Programming and its Rules: Skip to main content. Microcontroller has only one 8-bits data type and the size of each register is also 8 bits.


Like us on Facebook. The names used for labels asembler assembly language programming consists of alphabetic letters in both upper and lower case, the digits 0 through 9, and the special characters question mark [? First, each label name must be unique.

By choosing label names that are meaningful, a 80511 can make a program much easier to read and maintain. This indicates to the assembler the end of the source asm file. The job of the programmer is to break down data larger than 8 bits [00 to FFH, or 0 to in decimal] to be processed by the CPU.

The DB directive is the most widely used data assemblr in the assembler. END directive pseudocode is very important. Some assembler uses “. Rules for labels in Assembly language.

In addition to the mnemonics there are some other reserved words. What is the advantage of using EQU? Programmer can make a program easier to read and maintain by choosing label names that are meaningful.



END indicates to the assemblere the end of the source [asm directivew file. It is used to define the 8-bit data. The assembler will convert the numbers in hex.

The ORG directive is used to indicate the beginning of the address. Regardless of which is used, the assembler will convert the numbers into hex. The answer is that, lets say in a program there is a constant value [a fixed value] used in many different places in the program, and the programmer wants to change its value through out the entire directiives.

The ORG directive is used to indicate directivse beginning of the address. Every assembler has some reserved words that must not be used as labels in the program. Foremost among the reserved words are the mnemonics for the instructions. There are several rules that names must follow. In this section we look at some widely used data types and directives supported directlves the assembler.

For tha you need to check your assembler. Facebook Like For Iamtechnical.