AR# 32318: MIG v3.0, Virtex-5 QDRII - Design does not complete calibration in hardware when using Synplify Pro 9.6.2 as the synthesis tool
AR# 32318
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MIG v3.0, Virtex-5 QDRII - Design does not complete calibration in hardware when using Synplify Pro 9.6.2 as the synthesis tool
Description
There is a known issue when the MIG 3.0 Virtex-5 QDRII design is synthesized using Synplify Pro 9.6.2. This version of Synplify Pro fails to generate the negative edge of clk0. This clock is needed to clock the output address and command signals. Instead, the positive edge of clk0 is used to clock out the outputs, which causes these signals to fail setup time at the QDRII memory. As a result, the design is stuck in calibration.
Solution
To work around this Synplify Pro issue, add a temporary signal called 'clk_temp' with a syn_keep attribute in the infrastructure.v module. The existing assignment for clk180 needs to be commented out and the value of clk_temp signal, then assigned to the clk180 (an output of the infrastructure.v) module.
Make the following code changes in the infrastructure.v module: