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AR# 32023

LogiCORE SPI-4.2 (POS-PHY L4) Lite v4.3 - Virtex-4 or Virtex-5 core may fail in hardware


The SPI-4.2 Lite core may see DCM-related issues in hardware (like failure to lock or incorrect output frequency). The issues only occur in Virtex-4 or Virtex-5 architectures.


This issue is caused by an incorrect setting in the core for the DLL_FREQUENCY_MODE attribute of the DCM. The attribute is currently set to LOW, but should be set to HIGH for Virtex-4 and Virtex-5 cores. 


The workaround is to add the constraint DLL_FREQUENCY_MODE = HIGH in the UCF file for both the Source and Sink Core DCMs. For example: 


INST "pl4_lite_snk_clk0/rdclk_dcm0" DLL_FREQUENCY_MODE = HIGH;  


INST "pl4_lite_src_clk0/tdclk_dcm0" DLL_FREQUENCY_MODE = HIGH; 


This issue will be fixed in the next core release.

AR# 32023
Date Created 01/06/2009
Last Updated 05/23/2014
Status Archive
Type General Article