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AR# 29362

14.x Timing Analysis - "WARNING:Timing:3224 - The clock 'CLOCK' associated with '%s' does not clock any registered '%s' components"

Description

The following warning is reported in the timing report:

WARNING:Timing:3224 - The clock CLKIN associated withTIMEGRP "datain_registers" OFFSET = IN 3ns BEFORE COMP "CLKIN" HIGH;does not clock any registered input components.

The constraints referenced in the UCF are as follows:

NET "CLKIN" TNM_NET = datain_registers;
TIMEGRP "datain_registers" OFFSET = IN 3ns BEFORE "CLKIN" HIGH;

Solution

The syntax of this OFFSET IN constraint is incorrect. Remember to place the referred register group on the right side of the equation and the pad group on the left side of the equation. The correct syntax is as follows:

[TIMEGRP "padgroup_name"] OFFSET=IN time unit BEFORE pad_clock_netname [TIMEGRP "reg_group_name"];

In this example, datain_registers is a register group clocked by CLKIN. It does not contain any pad components. So, the OFFSET IN constraint does not cover any input paths. This is the same as the OFFSET OUT constraint.

If the clock path involves a clock management component, for example, DCM, PLL, and MMCM, ensure that the period constraint for the input clock net is propagated to the clock that actually drives the input registers.

AR# 29362
Date Created 09/17/2007
Last Updated 11/23/2016
Status Active
Type General Article
Tools
  • ISE - 10.1
  • ISE Design Suite - 11.1
  • ISE Design Suite - 11.2
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