Default User Control Settings - 2021.2 English

Vitis High-Level Synthesis User Guide (UG1399)

Document ID
UG1399
ft:locale
English (United States)
Release Date
2021-12-15
Version
2021.2 English

The default global option configures the solution for either Vitis application acceleration development flow or Vivado IP development flow.

open_solution -flow_target [vitis | vivado]

This global option is replacing the old config option (config_sdx).

Vivado Flow:

Configures the solution to run in support of the Vivado IP generation flow, requiring strict use of pragmas and directives, and exporting the results as Vivado IP. The command to set up the project solution for the Vivado IP flow is:

open_solution -flow_target vivado

The table below shows the original default settings of command options in the Vivado HLS tool, and the new defaults found in the Vitis HLS tool.

Table 1. Default Control Settings
Default Control Settings Vivado HLS Vitis HLS
config_compile -pipeline_loops 0 64
config_export -vivado_optimization_level 2 0
set_clock_uncertainty 12.5 27%
config_interface -m_axi_alignment_byte_size N/A 0
config_interface -m_axi_max_widen_bitwidth N/A 0
config_export -vivado_phys_opt place none
config_interface -m_axi_addr64 false true
config_schedule -enable_dsp_full_reg false true
config_rtl -module_auto_prefix false true
interface pragma defaults ip mode ip mode

Vitis Flow (Kernel Mode):

Configures the solution for use in the Vitis application acceleration development flow. This configures the Vitis HLS tool to properly infer interfaces for the function arguments without the need to specify the INTERFACE pragma or directive, and to output the synthesized RTL code as a Vitis kernel object file (.xo). The command to set up the project solution for the Vitis kernel flow is:

open_solution -flow_target vitis

The table below shows the original default settings of command options in the Vivado HLS tool, and the new defaults found in the Vitis HLS tool.

Table 2. Default Control Settings
Default Control Settings Vivado HLS Vitis HLS
interface pragma defaults ip mode kernel mode (check default interfaces)
config_interface -m_axi_offset N/A direct
config_interface -m_axi_alignment_byte_size N/A 64
config_interface -m_axi_max_widen_bitwidth N/A 512
config_compile -name_max_length 256 255
config_compile -pipeline_loops 64 64
set_clock_uncertainty 27% 27%
config_rtl -register_reset_num 3 3
config_interface -m_axi_latency 0 64