Using the Section Directive · Setting up the Linker · Running the Assembler from the Command Line MICROPROCESSOR INSTRUCTION REFERENCE ACI. The most commonly used assembler directives are ORG, DB, DW, EQU, and END. For example, 0 ORG C 1 00H directive informs the assembler to assemble. Assembly Language Format Assembler Example Description. Directive. ORG ( Origin) ORG H The *Please Refer to Assembly Code Summary.
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DT — Define Ten Bytes. Its format is as follows: INCLUDE- This directive is used to tell the assembler to insert a block of source code from the named file into the current source module. DATA- This directive indicates the beginning of the data segment.
This directive is used with name of the segment to indicate the end of that logic segment. The works directly with only 4 physical segments: If the word starts at an odd address, the will take 2 bus cycles to get the data. Each memory model microprocsesor various limitations depending on the maximum space available for code and data. You get question papers, syllabus, subject analysis, answers – all in one app.
This directive is used to group the logical segments named after the directive into one logical group segment. This directive diretcives used to declare a byte type variable or to store a byte in memory location.
This directive is used to define a variable which is 10 bytes in length or to reserve 10 bytes of storage in the memory. This directive is used to define a variable of type quadword or to reserve storage location of type quadword in memory.
DD — Define Doubleword. As the name says, it directs the assembler to do a task. Define Ten bytes [DT]- It is used to define the data items that are 10 bytes long. This shortens the source code. Mohaimen Himu October 24, at END- This is placed at the end of a source and it acts as the last statement of a program. DW — Define Word. Download our mobile app and study on-the-go. ALIGN- This directive will tell the assembler to align the next instruction on an address which corresponds to the given direcgives.
This directive instructs the assembler to increment the location of micdoprocessor counter to the next even address if it is not already in the even address.
8085 Assembler User Guide
It consists of the entire instruction set of EVEN This directive instructs the assembler to increment the location of the counter to the next even address if it is not already in the even address.
When EVEN is used the location counter will simply incremented to next address and NOP instruction is inserted in that incremented location.
This directive is used to give a name to some value or to a symbol. Newer Post Older Post Microrocessor. DB — Define Byte. Rest will be added with time……. Engineering in your pocket Download our mobile app and study on-the-go. Define Double word [DD]- It defines the data items that are a double word four bytes in length. This directive is used to define a variable of type doubleword or to reserve storage location of type doubleword in memory.
Executable statements- These are the statements to be executed by the processor. CODE [name] The name in this format is optional.
Assembler User Guide
DD — Define Doubleword This directive is used to define a variable of type doubleword or to reserve storage location aasembler type doubleword in memory. Write short notes on assembler directives.
If the word is at even address can read a memory in 1 bus cycle. This is because the END directive terminates the entire program.