x86 data types is a little bit different from MIPS assembly data type explained previously. 8086 data types have similar functionality but they are a little bit different in syntax.
These variable types are explained below:
See the table for the list of data type 8086 architecture offers.
| Pseudo-operation | Stand For |
|---|---|
| DB | Define Byte |
| DW | Define Word |
| DD | Define Doubleword |
| DQ | Define Quadword |
| DT | Define Ten Byte |
In addition to these data types, there is variable representation against each data type.
Variable Types in 8086 Assembly
Variable play same role in assembly language as in high-level languages. Each variable has a data type and assigned a space in memory. Variable types in x86 are explained below:
Byte Variable in x86
| DECIMAL RANGE FOR BYTE VARIABLE | |
|---|---|
| Signed Interpretation | -128 to 127 |
| Unsigned Interpretation | 0 to 255 |
Byte variable has the following general form:
name DB initial_value
We have a variable name, DB stands for “Define Byte” and an initial value of a variable. See the example below in which a byte variable is initialized.
variable1 DB 23
In the above example, the variable name is “varibale1” and its value is “23”. when you only need to declare a variable use a question mark(?) instead of a value.
variable DB ?
Word Variable in x86
| DECIMAL RANGE FOR WORD VARIABLE | |
|---|---|
| Signed Interpretation | -32768 to 32767 |
| Unsigned Interpretation | 0 to 65535 |
DW is used for a word variable. Its Basic form is as follows:
name DW initial_value
It is 32 bit so you can also use signed value as given below:
variable DW -23
Ask your problems in the comment box below.