User`s guide

Known Software Problems
13-15
Known Software Problems
The following sections describe some of the known DSP Blockset problems and
limitations:
•“Real-Time Workshop C Code Generation Limitations”
•“Nonzero Simulation Start Times Not Supported”
•“Triggered and Enabled Subsystem Support”
•“Digital Filter Design Block Limitations”
•“Magnitude FFT Block Limitations”
Real-Time Workshop C Code Generation Limitations
C code generated from DSP Blockset blocks using Real-Time Workshop has the
following limitations:
•DSP Blockset generally does not support the
Loop rolling threshold
parameter (visible when the
Category parameter is set to General code
generation options
) in the Real-Time Workshop tab of the Simulink
Simulation Parameters dialog.
•Currently, the DSP Blockset run-time library
dsp_rt.lib does not always
rebuild when you change compiler or linker options. Thus, before changing
compiler and linker options, you should delete
dsp_rt.lib and all associated
object files. You can change compiler and linker options in the Simulink
Simulation Parameters dialog’s Real-Time Workshop tab by setting make
command arguments such as
OPTS or OPT_OPTS in the Make command
parameter (for example,
make_rtw OPTS="-DMYDEFINE=1").
Nonzero Simulation Start Times Not Supported
The DSP Blockset does not support nonzero simulation start times. When
running a simulation with DSP Blockset blocks, you must set the
Start time
option in the Simulink
Simulation Parameters dialog’s Solver tab to 0.