Zilog EZ80F916 - Manual (Page 205)

UM014423-0607
ZiLOG Developer Studio II
eZ80Acclaim! ® User Manual
185
User-Defined Segments
You can define a new segment using the following directives:
DEFINE MYSEG,SPACE=ROM
SEGMENT MYSEG
MYSEG becomes the current segment when the assembler processes the
SEGMENT
direc-
tive, and MYSEG remains the current segment until a new
SEGMENT
directive appears.
MYSEG can be used as a segment name in the linker command file.
You can define a new segment in RAM using the following directives:
DEFINE MYDATA,SPACE=RAM
SEGMENT MYDATA
The
DEFINE
directive creates a new segment and attaches it to a space. For more informa-
tion about using the
DEFINE
directive, see “DEFINE” on page 203. The
SEGMENT
direc-
tive attaches code and data to a segment. The
SEGMENT
directive makes the segment
named in the directive the currently active segment. Any code or data following the
SEG-
MENT
directive resides in the segment until another
SEGMENT
directive is encountered. For
more information about the
SEGMENT
directive, see “SEGMENT” on page 208.
A segment can also be defined with a boundary alignment and/or origin:
•
Alignment
Aligning a segment tells the linker to place all instances of the segment in your
program on the specified boundary.
NOTE: Although a module can enter and leave a particular segment many times, the
module still has only one instance of that segment.
•
Origin
When a segment is defined with an origin, the segment becomes an absolute segment,
and the linker places it at the specified physical address in memory.
BSS RAM Uninitialized data
DATA RAM Initialized data
CODE ROM Code
Table 8. Predefined Segments (Continued)
Segment Name Address Space Contents