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- 15.3.12. Fully-Parallel FFTs with Flexible Ordering (FFT2X, FFT4X, FFT8X, FFT16X, FFT32X, and FFT64X)
- 15.3.13. General Multitwiddle and General Twiddle (GeneralMultiTwiddle, GeneralMultVTwiddle, GeneralTwiddle, GeneralVTwiddle)
9.9. About Importing HDL
Importing HDL has the following software requirements:
- HDL Verifier toolbox
- An HDL Verifier compatible version of the ModelSim simulator (importing HDL does not support ModelSim AE)
Additionally, your HDL must conform to DSP Builder design rules and must:
- Have only one clock domain
- Match reset level with DSP Builder
- Use the std_logic data type for clock and reset ports
- Use std_logic_vector for all other ports
- Have no top-level generics
- Contain no bus components
You may need to write a wrapper HDL file that instantiates your HDL, which might configure generics, convert from other data types to std_logic_vector, or invert the reset signal.
DSP Builder can import any number of instantiated entities. To import multiple copies of an entity or multiple distinct entities, instantiate the entities in a top-level wrapper file.
Simulink does not model all the signal states that ModelSim uses (e.g. ‘U’). Simulink interprets all non-‘1’ states as a ‘0’.
Importing HDL uses the HDL Verifier toolbox to communicate with an HDL simulation running in ModelSim. You can have as many components in your ModelSim simulation as you like; each component communicates with a separate DSP Builder HDL Import block. Your top-level design must include an HDL Import Config block.
You cannot place HDL Import blocks inside a primitive scheduled subsystem.
DSP Builder creates the appropriate instantiation of the component represented by the HDL Import block.
DSP Builder sees imported HDL as a scheduled system. DSP Builder does not try to schedule your imported HDL. You cannot import HDL into a scheduled subsystem. Imported HDL acts like other DSP Builder IP blocks (e.g. NCO, FFT). You must manually delay-balance any parallel datapaths and turn on Generate Hardware in the Control block.
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