Holtek HT-IDE, User Manual

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The following are the data types, sizes and range
Data Type Size (bits) Range
char 8 –128~127
unsigned char 8 0~255
int 8 –128~127
unsigned 8 0~255
short int 8 –128~127
unsigned short int 8 0~255
long 16 –32768~32767
unsigned long 16 0~65535
Declaration
Variables must be declared before being used as this defines the data type
and the size of the variable. The syntax of variable declaration is:
data_type variable_name [,variable_name...];
where data_type is a valid data type and variable_name is the name of
the variable. The variables declared in a function are private (or local) to
that function and other functions cannot access these variables directly.
The local variables in a function exist and are valid only when this function
is called, and are non-valid when exiting from the function. If the variable
is declared outside of all functions, then it is global to all functions.
The qualifier const can be applied to a declaration of any variable, to
specify that the value of the variable will not be changed. The variables
declared with const are placed within the ROM space. The const qualifier
can be used in array variables. A const variable must be initialized upon
declaration, followed by an equal sign and an expression. Other variables
cannot be initialized when declared.
A variable can be declared in a specified RAM address by using the ’@’
character; the syntax is:
data_type variable_name @ memory_location;
For example:
int lcd @ 0
×
20; /* declare the variable lcd in the offset
0
×
20 of RAM */
Also, an array can be declared in a specified location:
int port[8] @ 0
×
20; /* array port takes memory location
0
×
20 through 0
×
27 */
HT-IDE User’s Guide
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