Texas Instruments TMS320C54x, User Manual

Page: 318 / 469

The ROMS Directive
10-18
files identifies the names of the output files that correspond to this
range. Enclose the list of names in curly braces and order them
from
least significant to most significant output file.
The number of file names should equal the number of output
files that the range will generate. To calculate the number of
output files, refer to Section 10.4.4,
ROM Width, on page
10-11. The utility warns you if you list too many or too few file-
names.
Unless you are using the –image option, all of the parameters defining a range
are optional; the commas and equals signs are also optional. A range with no
origin or length defines the entire address space. In image mode, an origin and
length are required for all ranges.
Ranges on the same page must not overlap and must be listed in order of
ascending address.
10.5.1 When to Use the ROMS Directive
If you don’t use a ROMS directive, the utility defines a single default range that
includes the entire program address space (PAGE 0). This is equivalent to a
ROMS directive with a single range without origin or length.
Use the ROMS directive when you want to:
-
Program large amounts of data into fixed-size ROMs. When you spe-
cify memory ranges corresponding to the length of your ROMs, the utility
automatically breaks the output into blocks that fit into the ROMs.
-
Restrict output to certain segments. You can also use the ROMS direc-
tive to restrict the conversion to a certain segment or segments of the tar-
get address space. The utility does not convert the data that falls outside
of the ranges defined by the ROMS directive. Sections can span range
boundaries; the utility splits them at the boundary into multiple ranges. If
a section falls completely outside any of the ranges you define, the utility
does not convert that section and issues no messages or warnings. In this
way, you can exclude sections without listing them by name with the
SECTIONS directive. However, if a section falls partially in a range and
partially in unconfigured memory, the utility issues a warning and converts
only the part within the range.
-
Use image mode. When you use the –image option, you must use a
ROMS directive. Each range is filled completely so that each output file in
a range contains data for the whole range. Gaps before, between, or after
sections are filled with the fill value from the ROMS directive, with the value
specified with the –fill option, or with the default value of 0.