Configuring Bi-Directional Ports for Simulation - 2020.2 English

Vivado Design Suite User Guide: Model-Based DSP Design Using System Generator (UG897)

Document ID
UG897
Release Date
2020-11-18
Version
2020.2 English

Bidirectional ports (or inout ports) are supported only during the generation of the HDL netlist, that is, bi-directional ports will not show up in the System Generator diagram. By default, bi-directional ports will be driven with 'X' during simulation. It is possible to overwrite this behavior by associating a data file to the port. Be sure to guard this code because bi-directional ports can only be added to a block during the config_netlist_interface phase.

if (strcmpi(this_block.getConfigPhaseString,'config_netlist_interface'))
  bidi_port = this_block.port('bidi'); 
  bidi_port.setGatewayFileName('bidi.dat');
end

In the above example, a text file, bidi.dat, is used during simulation to provide stimulation to the port. The data file should be a text file, where each line represents the signal driven on the port at each simulation cycle. For example, a 3-bit bi-directional port that is simulated for 4 cycles might have the following data file:

ZZZ
110
011
XXX

Simulation will return with an error if the specified data file cannot be found.