General Description: I am describing a synchronous set and reset, which is valid in the Virtex architecture. After the optimize step, I am seeing the set signal and the data signal being implemented in a LUT instead of utilizing the Virtex-specific features. This is resulting in an increased LUT count, and area usage. (I am using Leonardo Spectrum 1998.2e.)
Solution
The Beta version contains fixes for inferring Xilinx Virtex flip-flops with synchronous set or reset. Currently, the Exemplar software cannot infer a Virtex-specific synchronous set and reset.
Possible work-arounds are to:
1. Instantiate the component. 2. Use the set include_gates "FDRSE FRSE FDRSE_1 FDSE_1" from the variable editor within the GUI or in the script.
NOTE: If Method 2 is used, the data and set signal may be swapped during synthesis; because of this, Step 1 is the recommended work-around.
Was this Answer Record helpful?
AR# 6840
Date
09/17/2002
Status
Archive
Type
General Article
By using this website, I accept the use of cookies.
Learn more