Assembler directives and operators are important components of the assembly language used in the Intel 8086 microprocessor. They allow programmers to perform a wide range of tasks, from defining data and variables to controlling the flow of a program. In this essay, we will explore the different types of assembler directives and operators available in the 8086 and how they are used in assembly language programming.
Assembler directives are commands that are used to provide information to the assembler, rather than being executed as part of the program. They are used to define data, allocate memory, and perform other tasks that are not related to the execution of the program. Some common assembler directives in the 8086 include:
DB (Define Byte): Used to define a byte of data.DW (Define Word): Used to define a word (two bytes) of data.DD (Define Doubleword): Used to define a doubleword (four bytes) of data.EQU (Equal): Used to define a symbol and assign it a value.ORG (Origin): Used to specify the starting address for the program.
Operators are used to perform operations on data and variables in a program. They can be used to perform arithmetic, logical, and bitwise operations, as well as to compare and manipulate data. Some common operators in the 8086 include:
- Arithmetic operators:
+, -, *, /, MOD (modulus) - Logical operators:
AND, OR, NOT - Bitwise operators:
AND, OR, NOT, XOR, SHL (shift left), SHR (shift right) - Comparison operators:
EQU, NE, LT, LE, GT, GE
In addition to these basic operators, the 8086 also supports a number of specialized operators, including SEG (segment operator) and OFF (offset operator), which are used to access memory segments and offsets in the program.
Overall, assembler directives and operators are crucial tools for programming in the 8086 assembly language. They allow programmers to define and manipulate data, control the flow of a program, and perform a wide range of operations on data and variables. Understanding how to use these tools is essential for anyone looking to write programs in the 8086 assembly language.
8086 note
What are the types of assemblers? CLI — Clear Interrupt Flag. LEA BX, TABLE1 MOV AL, 04H XLAT Input and output port transfer instructions : IN: Copy a byte or word from specified port to accumulator. There are 4 assembler directives and the comment tag. NEAR: This is used for intrasegment call i. Example: the code segment is used to indicate to the assembler the start of logical segment. DB, DW, and DD.
What are assembler directives in 8086? Explained by FAQ Blog
There are three types of assemblies: Private assemblies. Thereby informing the assembler that the data stored in memory is quad-word. SRAM has a smaller access time as it has an on-chip memory unit whereas DRAM has a larger access time as it has an off-chip memory. RCL CX, 1 MOV CL, 04H RCL AL, CL RCR Instruction: RCR destination, count This instruction rotates all bits in a specified byte or word some number of bit positions to the right along with the carry flag. Comparison Chart SRAM DRAM SRAM is really fast.
What are the different types of assembler directive?
At each iteration, CX is decremented automatically and JUMP IF NOT ZERO structure. There is no need for the refreshing of cycles to make the data retain. Types of different routines and modules End of file,………… etc. The BIOS routines are called with INT instructions. Advanced assemblers provide facilities like macros, lists,……… etc making the task of programming much easier. For directives no machine code is generated and no memory location is allocated.
Assembler Directives 8086 8086 Microprocessor
Example: SMALL-SYSTEM GROUP CODE, DATA, STACK-SEG. The PTR operator can be used to override the declared type of variable and also to clarify our intentions when we use indirect jump instructions. The stack pointer is decremented by 2, after each execution of the instruction. Here we discuss various assembler directives: ORG directive: This directive instructs the assembler to start the program in memory from the offset mentioned in the argument of ORG. As you might infer from the name high-level language, there are also low-level languages, sometimes referred to as machine languages or assembly languages. RAM has two main types; SRAM Static Random-Access Memory and DRAM Dynamic Random-Access Memory.
