Zilog ZUSBOPTS - Manual (Page 342)

Program Configurations UM017105-0511
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Zilog Developer Studio II – ZNEO™
User Manual
C Program Setup
The C program setup for the Download to ERAM Program Configuration is similar to the
Default Program Configuration with some additional steps as described in this section.
The C-Compiler by default generates the executable program code under one unified seg-
ment named CODE. The CODE segment belongs to EROM address space. To set up this
configuration, you must move this CODE segment from EROM to ERAM address space.
Do this by adding the following linker command in the
Additional Linker Directives dia-
log box (see the Additional Directives section on page 62):
change code=ERAM /* The linker will then allocate code segment in
ERAM */
To go back to the Default Program Configuration for production code, remove this direc-
tive from the
Additional Linker Directives dialog box.
Special Case: Partial Download to ERAM
A special case of this configuration is to download program code from just one C source
file into ERAM, while retaining the rest of the code in EROM. This example is included
for completeness because similar cases of partitioning the code are discussed for the other
configurations that are covered in this chapter.
Perform the following steps:
1. Select the Distinct Code Segment for Each Module checkbox in the Advanced
page in the Project Settings dialog box (discussed on page 59 ). This option directs
the C-Compiler to generate different code segment names for each file.
2. Use the linker CHANGE directive to move the particular segment to ERAM.
For example, to download the code for main.c to ERAM, add the following linker
command in the Additional Linker Directives dialog box (see Additional Directives
– see page 62):
change main_TEXT = ERAM
To go back to the Default Program Configuration for production code, remove this
directive from the
Additional Linker Directives dialog box.
Assembly Program Setup
The Assembly program setup for the Download to ERAM Program Configuration is simi-
lar to the Default Program Configuration with some additional guidelines, as described in
this section.
Write all of the executable program (non-start-up) code under the CODE segment. This
segment belongs to EROM address space. To set up this configuration, you must move the
CODE segment from EROM to the ERAM address space by adding the following linker