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AR# 55334

2013.x Vivado Synthesis - Known Issues

Description

This answer record lists known issues for 2013.x Vivado Synthesis.

Solution

2013.4 Vivado Synthesis Known Issues

(Xilinx Answer 62073) Vivado Synthesis - Optimization causes CARRY4 inputs to be connected incorrectly
(Xilinx Answer 58574) 2013.3 Vivado-Synthesis: Is there any limit on the minimum number of states required to infer FSM?
(Xilinx Answer 57981) Vivado Synthesis - Do we pack ROM into block RAM when there is an incompatible interface on the input side?
(Xilinx Answer 58691) Vivado Synthesis - A CRITICAL WARNING occurs stating that an existing primary or secondary unit is being overwritten [Synth 8-4527] or [Synth 8-4528]
(Xilinx Answer 57983) Vivado synthesis - Loose timing constraints results in LUTRAM instead of block RAM
(Xilinx Answer 57959) Vivado Synthesis - Fails to infer Block RAM when the RAM output is driving part of a register bus
(Xilinx Answer 57963) Vivado Synthesis - Unconnected pins on BlackBox.
(Xilinx Answer 57975) Vivado Synthesis - Issue with array of instances when using SystemVerilog unpacked arrays
(Xilinx Answer 57984) Does Vivado Synthesis support $clog2 function?
(Xilinx Answer 56211) Does Vivado Synthesis support two dimensional array initialization using reg declaration?
(Xilinx Answer 57964) Vivado Synthesis - Issue with VHDL Time data Type
(Xilinx Answer 57985) Vivado Synthesis - Tool is hanging during compilation of block of loops
(Xilinx Answer 58022) Vivado Synthesis - Netlist names for signals coming from VHDL record types have changed.
(Xilinx Answer 57727) Vivado Synthesis - Net names not preserved by mark_debug
(Xilinx Answer 56467) Vivado Synthesis - Why is unassigned debug nets found in the Vivado GUI when mark_debug attribute is applied on few ports of a submodule?
(Xilinx Answer 56456) Vivado Synthesis - How to manually setup my HDL files?
(Xilinx Answer 56457) Vivado Synthesis - Does Vivado Synthesis infer an optimal block RAM when both read address and the output data are registered in the HDL code?
(Xilinx Answer 55914) Vivado Synthesis - What is Vivado Synthesis's `include file search order for project, non-project modes?
(Xilinx Answer 54074) Vivado Synthesis - Synthesis give a "Module not found" error for an EDIF module.
(Xilinx Answer 55989) Vivado Synthesis - Why will a Xilinx IP not get flattened completely?
(Xilinx Answer 56371) Vivado Synthesis - How do you speed up XDC constraints processing during synthesis?
(Xilinx Answer 56370) Vivado Synthesis - "-verbose" switch of synth_design TCL command does not work correctly and what would be the alternate option?
(Xilinx Answer 55942) Vivado - Vivado Synthesis - Why are the inputs to my EDIF/NGC files left unconnected?
(Xilinx Answer 55203) Vivado - 2013.x Vivado Synthesis - What is the purpose of RuntimeOptimized option when passed to -directive switch?
(Xilinx Answer 55224) Vivado - 2013.x Vivado Synthesis - What is the purpose of "out_of_context" option used as part of the -mode switch?
(Xilinx Answer 55225) Vivado - Vivado Synthesis - How to get around longer constraint validation time during early development cycles?
(Xilinx Answer 51502) Vivado Synthesis - When will VHDL-2008 be supported in Vivado?
(Xilinx Answer 51163) Vivado Synthesis - MAX_FANOUT Synthesis Attribute not supported for edif netlist files
(Xilinx Answer 55302) Vivado Synthesis - Alternative HDL coding style to reduce longer runtimes.
(Xilinx Answer 55135) Vivado Synthesis - Unsupported SystemVerilog constructs
(Xilinx Answer 55196) Vivado Synthesis - What features are not supported by Vivado Synthesis for DSP48 inference?
(Xilinx Answer 55194) Vivado Synthesis - What are Vivado Synthesis best practices for SystemVerilog?
(Xilinx Answer 54551) Vivado Synthesis - How does Vivado Synthesis treat imported core netlists today?
(Xilinx Answer 53524) Vivado Synthesis - Does Vivado Synthesis merge multiple registers that are declared separately and used as the output register bus of a DSP48?
(Xilinx Answer 53505) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer a block RAM on an asynchronous reset output register?
(Xilinx Answer 53507) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer block RAM for multi-dimensional arrays greater than two dimensions?
(Xilinx Answer 52335) What are the recommended steps to be followed today in order to do bottom-up synthesis using the Vivado Synthesis tool?
(Xilinx Answer 52333) Why does Vivado Synthesis generate "ERROR: [Synth 8-2914] Unsupported RAM template" when more than two clocks are present within a block RAM memory inferring HDL code?
(Xilinx Answer 52331) Does Vivado Synthesis support VHDL record type to model a memory and infer a block RAM?
(Xilinx Answer 52304) Does Vivado Synthesis support IEEE MATH_REAL and PROPOSED package libraries?
(Xilinx Answer 52303) Does Vivado Synthesis support resettable memory array?
(Xilinx Answer 52301) Does Vivado Synthesis support the READ_CORES option?
(Xilinx Answer 46743) Would Vivado Synthesis be able to infer 3-state logic in a lower level design when flatten_hierarchy is set to none?
(Xilinx Answer 52086) Vivado Synthesis - WARNING: [Synth 8-1824] circular dependency found for file <name>.vhd  while ordering
(Xilinx Answer 47454) Vivado Synthesis - Does Vivado synthesis support Verilog Module instantiation in VHDL entity via work library?
(Xilinx Answer 51087) Does Vivado Synthesis tool support physical constraints?
(Xilinx Answer 51088) As part of True Dual Port RAM coding styles, does Vivado Synthesis tool generate RAMs when both ports are specified in the same always/process block?
(Xilinx Answer 60194) Vivado Synthesis - Optimization causes CARRY4 inputs to be connected incorrectly

2013.4 Vivado Synthesis Resolved Issues

(Xilinx Answer 58007) Vivado Synthesis - Some clarifications and explanation for "control_set_opt_threshold" and its workings
(Xilinx Answer 57972) Vivado Synthesis - Crash due to Syntax Error in a System Verilog code
(Xilinx Answer 60079) 2013.3 Vivado Synthesis - constant logic signals connected to Debug cores in the HDL are not preserved

2013.3 Vivado Synthesis Known Issues

(Xilinx Answer 57981) Vivado Synthesis - Do we pack ROM into BRAM when there is an incompatible interface on the input side?
(Xilinx Answer 57983) Vivado synthesis - Loose timing constraints results in LUTRAM instead of BRAM
(Xilinx Answer 57959) Vivado Synthesis - Fails to infer Block RAM when the RAM output is driving part of a register bus
(Xilinx Answer 57963) Vivado Synthesis - Unconnected pins on BlackBox.
(Xilinx Answer 57975) Vivado Synthesis - Issue with array of instances when using SystemVerilog unpacked arrays
(Xilinx Answer 57984) Does Vivado Synthesis support $clog2 function?
(Xilinx Answer 56211) Does Vivado Synthesis support two dimensional array initialization using reg declaration?
(Xilinx Answer 57972) Vivado Synthesis - Crash due to Syntax Error in a System Verilog code
(Xilinx Answer 57964) Vivado Synthesis - Issue with VHDL Time data Type
(Xilinx Answer 57985) Vivado Synthesis - Tool is hanging during compilation of block of loops
(Xilinx Answer 58007) Vivado Synthesis - Some clarifications and explanation for "control_set_opt_threshold" and its workings
(Xilinx Answer 58022) Vivado Synthesis - Netlist names for signals coming from VHDL record types have changed.
(Xilinx Answer 57727) Vivado Synthesis - Net names not preserved by mark_debug
(Xilinx Answer 56467) Vivado Synthesis - Why is unassigned debug nets found in the Vivado GUI when mark_debug attribute is applied on few ports of a submodule?
(Xilinx Answer 56456) Vivado Synthesis - How to manually setup my HDL files?
(Xilinx Answer 56457) Vivado Synthesis - Does Vivado Synthesis infer an optimal block RAM when both read address and the output data are registered in the HDL code?
(Xilinx Answer 55914) Vivado Synthesis - What is Vivado Synthesis's `include file search order for project, non-project modes?
(Xilinx Answer 54074) Vivado Synthesis - Synthesis give a "Module not found" error for an EDIF module.
(Xilinx Answer 55989) Vivado Synthesis - Why will a Xilinx IP not get flattened completely?
(Xilinx Answer 56371) Vivado Synthesis - How do you speed up XDC constraints processing during synthesis?
(Xilinx Answer 56370) Vivado Synthesis - "-verbose" switch of synth_design TCL command does not work correctly and what would be the alternate option?
(Xilinx Answer 55942) Vivado - Vivado Synthesis - Why are the inputs to my EDIF/NGC files left unconnected?
(Xilinx Answer 55203) Vivado - 2013.x Vivado Synthesis - What is the purpose of RuntimeOptimized option when passed to -directive switch?
(Xilinx Answer 55224) Vivado - 2013.x Vivado Synthesis - What is the purpose of "out_of_context" option used as part of the -mode switch?
(Xilinx Answer 55225) Vivado - Vivado Synthesis - How to get around longer constraint validation time during early development cycles?
(Xilinx Answer 51502) Vivado Synthesis - When will VHDL-2008 be supported in Vivado?
(Xilinx Answer 51163) Vivado Synthesis - MAX_FANOUT Synthesis Attribute not supported for edif netlist files
(Xilinx Answer 55302) Vivado Synthesis - Alternative HDL coding style to reduce longer runtimes.
(Xilinx Answer 55135) Vivado Synthesis - Unsupported SystemVerilog constructs
(Xilinx Answer 55196) Vivado Synthesis - What features are not supported by Vivado Synthesis for DSP48 inference?
(Xilinx Answer 55194) Vivado Synthesis - What are Vivado Synthesis best practices for SystemVerilog?
(Xilinx Answer 54551) Vivado Synthesis - How does Vivado Synthesis treat imported core netlists today?
(Xilinx Answer 53524) Vivado Synthesis - Does Vivado Synthesis merge multiple registers that are declared separately and used as the output register bus of a DSP48?
(Xilinx Answer 53505) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer a block RAM on an asynchronous reset output register?
(Xilinx Answer 53507) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer block RAM for multi-dimensional arrays greater than two dimensions?
(Xilinx Answer 52335) What are the recommended steps to be followed today in order to do bottom-up synthesis using the Vivado Synthesis tool?
(Xilinx Answer 52333) Why does Vivado Synthesis generate "ERROR: [Synth 8-2914] Unsupported RAM template" when more than two clocks are present within a BRAM memory inferring HDL code?
(Xilinx Answer 52331) Does Vivado Synthesis support VHDL record type to model a memory and infer a Block RAM?
(Xilinx Answer 52304) Does Vivado Synthesis support IEEE MATH_REAL and PROPOSED package libraries?
(Xilinx Answer 52303) Does Vivado Synthesis support resettable memory array?
(Xilinx Answer 52301) Does Vivado Synthesis support the READ_CORES option?
(Xilinx Answer 46743) Would Vivado Synthesis be able to infer tristate logic in a lower level design when flatten_hierarchy is set to none?
(Xilinx Answer 52086) Vivado Synthesis - WARNING: [Synth 8-1824] circular dependency found for file <name>.vhd  while ordering
(Xilinx Answer 47454) Vivado Synthesis - Does Vivado synthesis support Verilog Module instantiation in VHDL entity via work library?
(Xilinx Answer 51087) Does Vivado Synthesis tool support physical constraints?
(Xilinx Answer 51088) As part of True Dual Port RAM coding styles, does Vivado Synthesis tool generate RAMs when both ports are specified in the same always/process block?
(Xilinx Answer 60079) 2013.3 Vivado Synthesis - constant logic signals connected to Debug cores in the HDL are not preserved


2013.3 Vivado Synthesis Resolved Issues

(Xilinx Answer 52264) Does Vivado Synthesis support Asymmetric read/write port width BRAM inference?
(Xilinx Answer 56498) 2013.2 Vivado Synthesis - Why is shift register not inferred for a HDL design containing a clock enable in spite of setting the shreg_extract attribute to "yes"?
(Xilinx Answer 53956) Vivado - Vivado Synthesis - How to extract a shift register and how to control the threshold of register chain depth for SRL inference?
(Xilinx Answer 57980) 2013.2: Vivado Synthesis generates incorrect logic and connects output port to ground.

2013.2 Vivado Synthesis Known Issues

(Xilinx Answer 56498) 2013.2 Vivado Synthesis - Why is shift register not inferred for a HDL design containing a clock enable in spite of setting the shreg_extract attribute to "yes"?
(Xilinx Answer 56467) Vivado Synthesis - Why is unassigned debug nets found in the Vivado GUI when mark_debug attribute is applied on few ports of a submodule?
(Xilinx Answer 56456) Vivado Synthesis - How to manually setup my HDL files?
(Xilinx Answer 56457) Vivado Synthesis - Does Vivado Synthesis infer an optimal block RAM when both read address and the output data are registered in the HDL code?
(Xilinx Answer 55914) Vivado Synthesis - What is Vivado Synthesis's `include file search order for project, non-project modes?
(Xilinx Answer 54074) Vivado Synthesis - Synthesis give a "Module not found" error for an EDIF module.
(Xilinx Answer 55989) Vivado Synthesis - Why will a Xilinx IP not get flattened completely?
(Xilinx Answer 56371) Vivado Synthesis - How do you speed up XDC constraints processing during synthesis?
(Xilinx Answer 56370) Vivado Synthesis - "-verbose" switch of synth_design TCL command does not work correctly and what would be the alternate option?
(Xilinx Answer 55942) Vivado - Vivado Synthesis - Why are the inputs to my EDIF/NGC files left unconnected?
(Xilinx Answer 55203) Vivado - 2013.x Vivado Synthesis - What is the purpose of RuntimeOptimized option when passed to -directive switch?
(Xilinx Answer 55224) Vivado - 2013.x Vivado Synthesis - What is the purpose of "out_of_context" option used as part of the -mode switch?
(Xilinx Answer 55225) Vivado - Vivado Synthesis - How to get around longer constraint validation time during early development cycles?
(Xilinx Answer 51502) Vivado Synthesis - When will VHDL-2008 be supported in Vivado?
(Xilinx Answer 51163) Vivado Synthesis - MAX_FANOUT Synthesis Attribute not supported for edif netlist files
(Xilinx Answer 55302) Vivado Synthesis - Alternative HDL coding style to reduce longer runtimes.
(Xilinx Answer 55135) Vivado Synthesis - Unsupported SystemVerilog constructs
(Xilinx Answer 55196) Vivado Synthesis - What features are not supported by Vivado Synthesis for DSP48 inference?
(Xilinx Answer 55194) Vivado Synthesis - What are Vivado Synthesis best practices for SystemVerilog?
(Xilinx Answer 53956) Vivado - Vivado Synthesis - How to extract a shift register and how to control the threshold of register chain depth for SRL inference?
(Xilinx Answer 54551) Vivado Synthesis - How does Vivado Synthesis treat imported core netlists today?
(Xilinx Answer 53524) Vivado Synthesis - Does Vivado Synthesis merge multiple registers that are declared separately and used as the output register bus of a DSP48?
(Xilinx Answer 53505) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer a block RAM on an asynchronous reset output register?
(Xilinx Answer 53507) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer block RAM for multi-dimensional arrays greater than two dimensions?
(Xilinx Answer 52335) What are the recommended steps to be followed today in order to do bottom-up synthesis using the Vivado Synthesis tool?
(Xilinx Answer 52333) Why does Vivado Synthesis generate "ERROR: [Synth 8-2914] Unsupported RAM template" when more than two clocks are present within a BRAM memory inferring HDL code?
(Xilinx Answer 52331) Does Vivado Synthesis support VHDL record type to model a memory and infer a Block RAM?
(Xilinx Answer 52304) Does Vivado Synthesis support IEEE MATH_REAL and PROPOSED package libraries?
(Xilinx Answer 52303) Does Vivado Synthesis support resettable memory array?
(Xilinx Answer 52301) Does Vivado Synthesis support the READ_CORES option?
(Xilinx Answer 52264) Does Vivado Synthesis support Asymmetric read/write port width BRAM inference?
(Xilinx Answer 46743) Would Vivado Synthesis be able to infer tristate logic in a lower level design when flatten_hierarchy is set to none?
(Xilinx Answer 52086) Vivado Synthesis - WARNING: [Synth 8-1824] circular dependency found for file <name>.vhd  while ordering
(Xilinx Answer 47454) Vivado Synthesis - Does Vivado synthesis support Verilog Module instantiation in VHDL entity via work library?
(Xilinx Answer 51087) Does Vivado Synthesis tool support physical constraints?
(Xilinx Answer 51088) As part of True Dual Port RAM coding styles, does Vivado Synthesis tool generate RAMs when both ports are specified in the same always/process block?
(Xilinx Answer 57980) 2013.2: Vivado Synthesis generates incorrect logic and connects output port to ground.

2013.2 Vivado Synthesis Resolved Issues

(Xilinx Answer 51237) Does Vivado Synthesis support FSM Safe Implementation feature?
(Xilinx Answer 55687) Vivado - Vivado Synthesis - The tool fails with the message "Partitioning Double Buffer just destructed was checked out in ..\callPartitioner.cxx:159..."
(Xilinx Answer 53519) Vivado 2012.x - Vivado Synthesis - How does Vivado Synthesis treat KEEP or DONT_TOUCH on a state machine register upon turning on FSM extraction?
(Xilinx Answer 53546) Vivado 2012.x - Vivado Synthesis - Why does Vivado Synthesis generate multiple drivers when a multi-bit register containing a keep or syn_keep attribute is assigned in a bit slice way in more than two process or always block statements?
(Xilinx Answer 52307) Does Vivado Synthesis support FSM extraction by default?
(Xilinx Answer 54907) Vivado Synthesis - Incorrect logic is generated when converting an HDL code containing priority-mux into parallel mux as part of optimization
(Xilinx Answer 52305) Does Vivado Synthesis support LUT combining by default?
(Xilinx Answer 53503) Vivado 2012.x - Vivado Synthesis - Are null ranges supported by Vivado Synthesis?
(Xilinx Answer 52300) Vivado - Vivado Synthesis - Does Vivado Synthesis support import methods (SystemVerilog functions and tasks) from the System Verilog Interface?

2013.1 Vivado Synthesis Known Issues

(Xilinx Answer 55687) Vivado - Vivado Synthesis - The tool fails with the message "Partitioning Double Buffer just destructed was checked out in ..\callPartitioner.cxx:159..."
(Xilinx Answer 55942) Vivado - Vivado Synthesis - Why are the inputs to my EDIF/NGC files left unconnected?
(Xilinx Answer 55203) Vivado - 2013.x Vivado Synthesis - What is the purpose of RuntimeOptimized option when passed to -directive switch?
(Xilinx Answer 55224) Vivado - 2013.x Vivado Synthesis - What is the purpose of "out_of_context" option used as part of the -mode switch?
(Xilinx Answer 55225) Vivado - Vivado Synthesis - How to get around longer constraint validation time during early development cycles?
(Xilinx Answer 51502) When will VHDL-2008 be supported in Vivado?
(Xilinx Answer 51163) Vivado - Vivado_Synthesis - MAX_FANOUT Synthesis Attribute not supported for edif netlist files
(Xilinx Answer 55302) Vivado - Vivado Synthesis - Alternative HDL coding style to reduce longer runtimes.
(Xilinx Answer 55135) Vivado - Vivado Synthesis - Unsupported SystemVerilog constructs
(Xilinx Answer 55196) Vivado - Vivado Synthesis - What features are not supported by Vivado Synthesis for DSP48 inference?
(Xilinx Answer 55194) Vivado - Vivado Synthesis - What are Vivado Synthesis best practices for SystemVerilog?
(Xilinx Answer 53956) Vivado - Vivado Synthesis - How to extract a shift register and how to control the threshold of register chain depth for SRL inference?
(Xilinx Answer 54551) Vivado - Vivado Synthesis - How does Vivado Synthesis treat imported core netlists today?
(Xilinx Answer 53524) Vivado Synthesis - Does Vivado Synthesis merge multiple registers that are declared separately and used as the output register bus of a DSP48?
(Xilinx Answer 53505) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer a block RAM on an asynchronous reset output register?
(Xilinx Answer 53507) Vivado 2012.x - Vivado Synthesis - Does Vivado Synthesis infer block RAM for multi-dimensional arrays greater than two dimensions?
(Xilinx Answer 52335) What are the recommended steps to be followed today in order to do bottom-up synthesis using the Vivado Synthesis tool?
(Xilinx Answer 52333) Why does Vivado Synthesis generate "ERROR: [Synth 8-2914] Unsupported RAM template" when more than two clocks are present within a BRAM memory inferring HDL code?
(Xilinx Answer 52331) Does Vivado Synthesis support VHDL record type to model a memory and infer a Block RAM?
(Xilinx Answer 52304) Does Vivado Synthesis support IEEE MATH_REAL and PROPOSED package libraries?
(Xilinx Answer 52303) Does Vivado Synthesis support resettable memory array?
(Xilinx Answer 52301) Does Vivado Synthesis support the READ_CORES option?
(Xilinx Answer 52264) Does Vivado Synthesis support Asymmetric read/write port width BRAM inference?
(Xilinx Answer 46743) Would Vivado Synthesis be able to infer tristate logic in a lower level design when flatten_hierarchy is set to none?
(Xilinx Answer 52086) Vivado Synthesis - WARNING: [Synth 8-1824] circular dependency found for file <name>.vhd  while ordering
(Xilinx Answer 47454) Vivado Synthesis - Does Vivado synthesis support Verilog Module instantiation in VHDL entity via work library?
(Xilinx Answer 51087) Does Vivado Synthesis tool support physical constraints?
(Xilinx Answer 51088) As part of True Dual Port RAM coding styles, does Vivado Synthesis tool generate RAMs when both ports are specified in the same always/process block?
(Xilinx Answer 51237) Vivado Synthesis - Recommended use of default statement with no Safe Implementation

2013.1 Vivado Synthesis Resolved Issues

(Xilinx Answer 57976) Does Vivado Synthesis support wor, wand, triand, trior net data types?
(Xilinx Answer 53519) Vivado 2012.x - Vivado Synthesis - How does Vivado Synthesis treat KEEP or DONT_TOUCH on a state machine register upon turning on FSM extraction?
(Xilinx Answer 53546) Vivado 2012.x - Vivado Synthesis - Why does Vivado Synthesis generate multiple drivers when a multi-bit register containing a keep or syn_keep attribute is assigned in a bit slice way in more than two process or always block statements?
(Xilinx Answer 52307) Does Vivado Synthesis support FSM extraction by default?
(Xilinx Answer 54907) Vivado Synthesis - Incorrect logic is generated when converting an HDL code containing priority-mux into parallel mux as part of optimization
(Xilinx Answer 52305) Does Vivado Synthesis support LUT combining by default?
(Xilinx Answer 53503) Vivado 2012.x - Vivado Synthesis - Are null ranges supported by Vivado Synthesis?
(Xilinx Answer 52300) Vivado - Vivado Synthesis - Does Vivado Synthesis support import methods (SystemVerilog functions and tasks) from the System Verilog Interface?

Linked Answer Records

Child Answer Records

Answer Number Answer Title Version Found Version Resolved
55764 Vivado - 2013.x Vivado Synthesis -- RAM_STYLE attribute specified as Capital letters not working N/A N/A
AR# 55334
Date Created 04/02/2013
Last Updated 10/08/2014
Status Active
Type Known Issues
Tools
  • Vivado Design Suite - 2013.1
  • Vivado Design Suite - 2013.2
  • Vivado Design Suite - 2013.3
  • Vivado Design Suite - 2013.4