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AR# 16501

5.1i ISE, Project Navigator - DCM language template code does not simulate correctly in the DCM DFS mode


Keywords: Project Navigator, language templates, DCM, DFS, CLKFX, frequency, simulation

Urgency: Standard

General Description:
The VHDL language templates for the DCM DFS do not simulate and are not implemented correctly. In both the functional and post-place-and-route simulations, the outputs of the DCM are stuck at static zeros.


This problem with the language template for DCM DFS simulation is caused by missing generics (primarily, the missing CLK_FEEDBACK) and attributes.

You can work around this issue by adding the following the template:

Generic (
CLK_FEEDBACK : string := "NONE" );

-- Attributes
attribute DFS_FREQUENCY_MODE : string;
attribute CLKFX_DIVIDE : integer;
attribute CLKFX_MULTIPLY : integer;
attribute STARTUP_WAIT : string;

attribute DFS_FREQUENCY_MODE of U_DCM: label is "LOW";
attribute CLKFX_DIVIDE of U_DCM: label is 1;
attribute CLKFX_MULTIPLY of U_DCM: label is 4;
attribute STARTUP_WAIT of U_DCM: label is "FALSE";
attribute CLK_FEEDBACK : string;
attribute CLK_FEEDBACK of U_DCM: label is "NONE";
AR# 16501
Date Created 01/14/2003
Last Updated 02/07/2006
Status Archive
Type General Article