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AR# 31933

11.3 System Generator for DSP - Why do I receive an error message stating "Continuous sample times not allowed" when driving a Simulink Spectrum Scope with Xilinx System Generator blocks?


Why do I receive error messages when my Simulink model uses Simulink Spectrum Scope Blocks to plot the output of System Generator blocks?


Because of the interaction with the System Generator simulation solver and the MATLAB solver, some System Generator designs will appear to Simulink blocks with a continuous sample rate. 

When this occurs, you cannot directly connect the outputs of System Generator blocks directly to Simulink blocks such as the Spectrum Scope, because they cannot accept continuous sample times.  

To work around this issue, you can add a Simulink Zero Order Hold block, or any other Simulink block that samples the signal, which will sample the signal and allow it to drive blocks such as the Spectrum Scope. 

You can find the Zero-Order Hold block in the default Simulink > Discrete blockset.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
29595 Xilinx DSP Tools, System Generator for DSP, and AccelDSP Synthesis Tool - Release Notes and Known Issues N/A N/A
AR# 31933
Date Created 11/20/2008
Last Updated 09/03/2014
Status Active
Type General Article
  • System Generator for DSP - 13.1
  • System Generator for DSP - 13.2
  • System Generator for DSP - 13.3
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  • System Generator for DSP - 12.1
  • System Generator for DSP - 12.2
  • System Generator for DSP - 12.3
  • System Generator for DSP - 12.4
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