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AR# 55185

Design Assistant for Vivado Synthesis - Help with Vivado Synthesis's equivalent RTL/GUI/TCL options for XST


This answer record provides information on some Vivado Synthesis switch options (RTL, GUI, TCL) equivalent to XST.

The answer record provides a tabular column comparing XST and Vivado Synthesis switch options, which can be used as a reference when a user transitions from XST to Vivado Synthesis and is in need of a quick reference guide.

This answer record will serve that purpose.

Note: This Answer Record is a part of the Xilinx Solution Center for Vivado Synthesis (Xilinx Answer 55265), which is available to address all questions related to Vivado Synthesis.

Whether you are starting a new design or troubleshooting a problem, use the Solution Center for Vivado Synthesis to guide you to the right information.


Below is a table of equivalent switches:

Name XST Equivalent Vivado Equivalent Available for
keep_hierarchy keep_hierarchy (RTL/GUI) keep_hierarchy (RTL), -flatten_hierarchy (GUI/TCL) VHDL, Verilog
black box BoxType (RTL) black_box (RTL) VHDL, Verilog
buffer type buffer_type (RTL) NA VHDL, Verilog
full case vldcase (GUI), full_case (RTL) full_case (RTL) Verilog
gated clock N/A gated_clock_conversion, gated_clk (RTL/GUI/TCL) VHDL, Verilog
Keep Keep (RTL) keep (RTL) VHDL, Verilog
Max fanout max_fanout (RTL/GUI) fanout_limit (TCL/GUI), MAX_FANOUT (RTL) VHDL, Verilog
Parallel Case vldcase (GUI), parallel_case (RTL) parallel_case (RTL) Verilog
RAM Style ram_style (RTL/GUI) ram_style (RTL), ram_style (TCL - Hidden) VHDL, Verilog
ROM Style rom_style (RTL/GUI) rom_style (RTL) VHDL, Verilog
Translate off, Translate on synthesis translate_off, synthesis translate_on (RTL) synthesis translate_off, synthesis translate_on (RTL) VHDL, Verilog
use dsp48 use_dsp48 (RTL/GUI) use_dsp48 (RTL) VHDL, Verilog
add IO buffers iobuf (GUI) no_iobuf (GUI/Tcl - Hidden), -mode out_of_context (Tcl/GUI - Recommended) VHDL, Verilog
FSM Extraction/ FSM Style fsm_extract (RTL/GUI) fsm_extraction (GUI/TCL) VHDL, Verilog
Equivalent Register Removal equivalent_register_removal (RTL/GUI) keep_equivalent_registers (GUI/TCL) VHDL, Verilog
Resource Sharing resource_sharing (RTL/GUI) resource_sharing (TCL/GUI) VHDL, Verilog
Generate RTL Schematic rtlview (GUI) -rtl (TCL) VHDL, Verilog
BUFG bufg (GUI) bufg (TCL/GUI) VHDL, Verilog
Netlist Hierarchy netlist_hierarchy (GUI) N/A VHDL, Verilog
Verilog Include Directories vlgincdir (GUI) include_dirs (TCL), Verilog options - verilog_dir (GUI) Verilog
Generics generics (RTL/GUI) generic (RTL/TCL) VHDL, Verilog
Verilog Macros define (GUI) verilog_define (TCL) Verilog
Optimization Effort opt_level (RTL/GUI) effort_level (TCL - Hidden) VHDL, Verilog
BRAM Utilization bram_utilization_ratio (GUI) max_bram (TCL - Hidden) VHDL, Verilog
DSP Utilization dsp_utilization_ratio (GUI) max_dsp (TCL - Hidden) VHDL, Verilog
Safe Implementation safe_implementation (RTL/GUI) fsm_safe_state (RTL/TCL) VHDL, Verilog
Shift Register Extraction shreg_extract (RTL/GUI) shreg_extract (RTL/TCL) VHDL, Verilog
Shift Register Minimum Size shreg_min_size (GUI) shreg_min_size (GUI/TCL) VHDL, Verilog
LUT Combining lc (GUI) no_lc (GUI/TCL) VHDL, Verilog
Reduce Control Sets reduce_control_sets (GUI) control_set_opt_threshold (GUI/TCL) VHDL, Verilog
Directive N/A directive (GUI/TCL) VHDL, Verilog
Don't Touch N/A dont_touch (RTL/TCL) VHDL, Verilog
FSM Encoding fsm_encoding (RTL/GUI) fsm_encoding (RTL) VHDL, Verilog
SRL Style N/A srl_style (RTL) VHDL, Verilog
Buffer Insertion N/A io_buffer_type (RTL) VHDL, Verilog
Clock buffer insertion N/A clock_buffer_type (RTL) VHDL, Verilog
Direct Enable N/A DIRECT_ENABLE (RTL) VHDL, Verilog
Direct Reset N/A DIRECT_RESET (RTL) VHDL, Verilog
Cascade DSP N/A cascade_dsp(GUI) VHDL, Verilog

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
55264 Xilinx Solution Center for Vivado Synthesis - Design Assistant N/A N/A
AR# 55185
Date Created 03/27/2013
Last Updated 01/20/2016
Status Active
Type Solution Center
  • Vivado Design Suite