Default Settings of Vivado/Vitis Flows - 2023.2 English

Vitis High-Level Synthesis User Guide (UG1399)

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2023.2 English

The default settings of the tool vary between the Vivado IP flow and the Vitis Kernel flow. The following table shows the default settings of both flows so that you can quickly determine the differences in the default configuration.

Tip: Beyond the default configuration, there are additional features of the tool that supports one flow, but not the other, or are configured differently between the two flows. Those differences are highlighted throughout this document.
Table 1. Default Configuration
Configuration Vivado Vitis
clock_uncertainty 27% 27%
syn.compile.pipeline_loops 64 64
syn.compile.name_max_length 255 255
vivado.optimization_level 0 0
vivado.phys_opt none none
syn.rtl.module_auto_prefix true true
syn.rtl.register_reset_num 0 3
syn.schedule.enable_dsp_full_reg true true
syn.directive.interface IP mode Kernel mode
syn.interface.m_axi_addr64 true true
syn.interface.m_axi_latency 0 64
syn.interface.m_axi_alignment_byte_size 1 64
syn.interface.m_axi_max_widen_bitwidth 0 512
syn.interface.default_slave_interface s_axilite s_axilite
syn.interface.m_axi_offset slave slave

Beyond these default settings, you must also package the generated RTL files for use in downstream processes, such as Vivado designs integrating multiple RTL files or Vivado IP into a single design. Or a Vitis kernel integrated with other PL kernels and an AI Engine graph application in a System project. The generated output is determined by the package.output.format and package.output.syn settings, as described in Packaging the RTL Design. The output format lets you create a packaged format from the RTL files of the design. The default output format is the Vivado IP .zip file format, which can be added to your IP catalog, and used in Vivado IP integrator features. You can also specify the output format as XO format to package the RTL files as a kernel for use in the Vitis development flow. The selection of flow_target does not automatically specify the output format. You must do this yourself.