Important Assembler Directives of the Microprocessor Data declaration directives: DB, DW, DD, DQ, DT ASSUME END directives EQU. The words defined in this section are directions to the assembler, not instructions for the Richa Upadhyay Prabhu. Microprocessors. Introduction To Segmentation: The microprocessor has 20 bit . The DW directive is used to tell the assembler to define a variable of type.
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The above directive tells the assembler that the name of the stack segment used by the programmer is STACK. Without this WORD addition, the segment will be located on the next available paragraph byte address, which might waste as much as 15 bytes of memory. This multiplication process takes place in the adder and thus a 20 bit number direcyives generated. Assember there are multiple values, ten consecutive memory locations are reserved for each value.
the use of assembler directives in microprocessor
They generate and store information in the memory. A carriage return is used after the END directive. But leave the bytes un-initialized. Furthermore, the question mark? Each module is individually assembled, tested, and debugged. A procedure may be an independent program module to give certain result or the required value to the calling program. The DS register data segment register is to be loaded with the starting address of the data segment, given by the operating system for the label DATA in the program.
The assembler will then put this information in the object code file so that the linker can connect the two modules together. The number is repeated five times. If there azsembler multiple values, 8 bytes of memory space are reserved for each value. This term paper includes the use of assembler directives in microprocessor and the various assembler directives used in Intel microprocessorits format with various microprocesslr.
This is called the base address. It has been defined with EQU directive in another program module. The directive DW defines a word -type variable. Hence, the two bytes of memory space contain H.
The above directive informs assembler to reserve 10 asseembler of consecutive memory locations for the variable named NUMBER and initialize with the above specified values. The directive PROC indicate the start of a procedure. The type NEAR is used to call a procedure which is within the program module. There are several other models too. This is used after the last statement of the program module.
the use of assembler directives in microprocessor | CustomWritings
The defined variable may have one or more initial values in the directive statement. The code segment registers are used to hold programs,data segment register to keep data, stack segment register for stack operations and extra segment register to keep strings of data.
There are some instructions in micropricessor assembly language program which are not a part of processor instruction set. Learn How to Order Essay Online.
It will initialize the 10 bytes with the values 11, 22, 33, 44, 55, 66, 77, 88, 99, and 00 when the program is loaded into memory to be run.
This directive informs assembler to reserve one byte of memory space for the variable named WEIGHT and initialize with value The memory locations are to be initialized with the values 32, 42, 59, 67 and The PUBLIC directive is used to tell the assembler that a specified name or label will be accessed from other modules. If there is only one value, 8 bytes of consecutive memory locations are reserved.
Therefore, the programmer should use END directive at the very end of his program module. The operating system that actually has the control of the memory, mcroprocessor is to be allotted to the program for execution, passes the memory address at which the program is to be loaded for execution and the map of the available memory to the loader.
They indicate how an operand or a section of program is to be processed by the assembler. This is a user micorprocessor segment name. Normally the data is variable. Micfoprocessor the directive statement there may be one or more values. The above directive informs assembler to reserve 8 bytes of consecutive memory locations for the variable named NUMBER and initialize with the above mentioned number. The label is used as prefix with directive ENDP.
The defined variable may have one or more values in the statement. When all the modules are working correctly, their object code files are linked together to form the complete 886.
If there are multiple values, two bytes of memory space are reserved for each value. If there are multiple values, four bytes of memory locations are reserved for each value. This directive informs assembler to reserve 16 bytes of consecutive memory locations.
The assembler prepares the relocation and linkages information subroutine, ISR for loader. This name is a user defined segment directices. A carriage return is required after the END directive. If there is only one value, 10 bytes of consecutive memory locations are reserved. It contains data of the program which is being executed.
To this a bit offset is added to generate the bit physical address. The general format of the PROC directive is:. The above directive informs assembler to reserve four bytes of memory locations for the variable named NUMBER and initialize with the number This assembler ignores statement s after an END directive. It is the directvies of the assembler designer to select the suitable strings for using them as directives,pseudo operands or reserved words and decides syntax.