Script for Laboratory: Designing embedded ASIPs - CES

• Always have a look at the printed warnings when dlxsim runs the simulation. At the end
of every simulation the warnings are summarized, i.e. the number of the printed warnings
is shown. If the simulations aborts before its usual end this summary is not printed. To see
the summary you can see them in the statistics with “stats warnings”.
Changing the source code to find the bug:
• When your CoSy compiled program is not running as expected then there are different
possible steps to find the problem. First, you should try to locate which code is causing
the problem. Therefore, you should find a minimal C-code that still causes the problem.
The further steps are much easier when the created assembly code is as small as possible.
• You have to understand, what the assembly code is doing to find and understand the error.
The output of a compiler is usually very difficult to read and to understand. Sometimes it
is very helpful to use SINAS (Support for Inline Assembly) to make the code more readable.
With SINAS, you can add your own assembler instructions or comments to the created
assembly code. With SINAS, you can also force the compiler not to rearrange the
created assembly code for optimizations. For example:
asm int addComment() {
@[.barrier]
; COMMENT: Between the i- and the j-loop
}
void main() {
for (int i=0; i