AR# 69583

Vivado Constraints - create_clock/create_generated_clock Master Answer Record


This Answer Record lists the common use cases and common issues of create_clock and create_generated_clock constraints.


Common Use Cases of create_clock

(Xilinx Answer 64340) Vivado Constraints - Frequently Asked Questions and Common Issues of the create_clock constraint
(Xilinx Answer 59799) Vivado Constraints - How to avoid overwriting clock constraints when using create_clock constraints in scoped constraint files?
(Xilinx Answer 64351) Vivado Constraints - How to constrain Gigabit Transceiver output clocks?

Common Issues with create_clock

(Xilinx Answer 55248) Vivado Timing and IP Constraints - Why do I get the following CRITICAL WARNING: [Vivado 12-259] No clocks specified,? please specify clocks, for my IP, or why do I get CRITICAL WARNING: [Vivado 12-1387] No valid object(s) found for set_max_delay?
(Xilinx Answer 57056) Vivado Constraints - Warning:[Vivado 12-627] No clocks matched 'xxxx'
(Xilinx Answer 59030) 2013.4 Vivado Timing - How do different startpoints of create_clock command affect the timing accuracy?
(Xilinx Answer 63960) FIFO Generator v12.0 - [Common 17-55] 'get_property' expects at least one object.[axis_fifo_32x16_clocks.xdc]
(Xilinx Answer 65163) Vivado Constraints - Critical Warning:[Constraints 18-1055] Clock 'top_clk' completely overrides clock 'clk', which is referenced by one or more other constraints. Any constraints that refer to the overridden clock will be ignored.
(Xilinx Answer 53805) Vivado Constraints - Why is the defined clock not seen in report_clock result?

Common Use Cases of create_generated_clock

(Xilinx Answer 62488) Vivado Constraints - Common Use Cases of create_generated_clock command
(Xilinx Answer 59484) Vivado - Constraint methodology for clock driven by cascaded BUFGMUX
(Xilinx Answer 52440) 2012.2 Vivado - What is the difference between -combinational and -divide_by while using create_generated_clock?
(Xilinx Answer 57197) Vivado Timing - How to rename the generated clock that is automatically created by the tool

Common Issues with create_generated_clock

(Xilinx Answer 60269) 2014.1 Vivado - create_generated_clock is not accepted by synthesis. Incorrect set of required parameters for "create_generated_clock"
(Xilinx Answer 54090) Vivado Constraints - "ERROR: [Common 17-161] Invalid option value '6.5' specified for 'multiply_?by'." received on create_generated_clock constraint
(Xilinx Answer 62528) Vivado Constraints - Critical Warning:[Constraints 18-551] Could not find an automatically derived clock matching the supplied criteria for renaming
(Xilinx Answer 67906) Vivado Constraints - generated clock for the forwarded clock refers to wrong master clock
(Xilinx Answer 62537) Vivado Constraints - Critical Warning:[Constraints 18-852]Found more than one automatically derived clock matching the supplied criteria for renaming
AR# 69583
Date 08/15/2017
Status Active
Type General Article