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AR# 21664

LogiCORE Tri-Mode Ethernet MAC v2.1 Core - Problem with ".ucf" constraint file for Spartan-3E which causes setup/hold errors in simulation

Description

General Description:

A problem exists with the ".ucf" constraint file generated for the LogiCORE Tri-mode Ethernet MAC v2.1 when targeted to a Spartan-3E device. Specifically, the problem is that the design has setup and hold errors in simulation, with warnings similar to the ones below, even though the design meets all timing constraints in timing analysis. In addition, the design successfully met timing and simulated in 7.1i Service Pack 2, but now fails in 7.1i Service Pack 3.

Simulation Warnings:

# ** Warning: /X_SFF SETUP High VIOLATION ON SSET WITH RESPECT TO CLK;

# Expected := 0.965 ns; Observed := 0.86 ns; At : 1798.599 ns

# Time: 1798599 ps Iteration: 3 Instance: /testbench/dut/design_example_client_side_fifo_tx_fifo_i_write_data_valid_int_9264

# ** Warning: /X_SFF SETUP Low VIOLATION ON SSET WITH RESPECT TO CLK;

# Expected := 0.965 ns; Observed := 0.86 ns; At : 1806.599 ns

# Time: 1806599 ps Iteration: 3 Instance: /testbench/dut/design_example_client_side_fifo_tx_fifo_i_write_data_valid_int_9264

# ** Warning: /X_SFF HOLD Low VIOLATION ON I WITH RESPECT TO CLK;

Solution

A patch is available to resolve this issue.

To obtain this fix, install the patch that is available in the LogiCORE Tri-mode Ethernet MAC v2.1 Core Release Notes and Known Issues Answer Record (Xilinx Answer 21044) and then regenerate the core.

AR# 21664
Date Created 09/04/2007
Last Updated 12/15/2012
Status Active
Type General Article