Holtek HT-IDE, User Manual

Page: 133 / 258

•
Example
PUBLIC start, setflag
EXTERN tmpbuf:byte
CODE
.SECTION ’CODE’
start:
mov a, 55h
call
setflag
....
setflag proc
mov tmpbuf, a
ret
setflag endp
end
In this example, both the label ’start’ and the procedure ’setflag’ are
declared as public variables. Programs in other sources may refer to these
variables. The variable ’tmpbuf’ is also declared as external. There should
be a source file defining a byte that is named tmpbuf and is declared as a
public variable.
→
Syntax
name
PROC
name
ENDP
•
Description
The PROC and ENDP directives mark a block of code which can be called or
jumped to from other modules. The PROC creates a label name which stands
for the address of the first instruction of a procedure. The assembler will set
the value of the label to the current value of the location counter.
•
Example
toggle PROC
mov tmpbuf, a
mov a, 1
xorm a, flag
mov a, tmpbuf
ret
toggle
ENDP
→
Syntax
[
label:]
DC
expression1 [,expression2 [,...]]
•
Description
The DC directive stores the value of expression1, expression2 etc. in
consecutive memory locations. This directive is used for the CODE sec-
tion only. The bit size of the result value is dependent on the ROM size of
the microcontroller, specified by the directive .CHIP or the command line
parameter /CHIP=. The HASM will clear any redundant bits; expression1
has to be a value or a label. This directive may also be employed to set up
the table in the code section.
Chapter 10 Assembly Language and Cross Assembler
123