Answers Database
A1.5/F1.5 PAR - PAR_NOGENRAMBLOCK environment variable
Record #4822
Product Family: Software
Product Line: FPGA Implementation
Product Part: par
Product Version: 1.5
Problem Title:
A1.5/F1.5 PAR - PAR_NOGENRAMBLOCK environment variable
Problem Description:
Urgency: standard
General Description:
What is the function of the PAR_NOGENRAMBLOCK environment
variable?
Solution 1:
In the M1.5 release of the Xilinx software, PAR specifically
looks for distributed RAM structures in an input design, and
internally builds each one up as a macro. It then places each
distributed RAM macro as a whole, rather than as a collection
of individual CLBs.
Typically this improves the performance of designs with large
distributed RAM structures in them. However, for certain
design topologies this can sometimes decrease performance.
Because of this possibility, when PAR builds these RAM
structures, it also informs the user that they may disable
the formation of the macros by setting a PAR_NOGENRAMBLOCK
environment variable.
End of Record #4822 - Last Modified: 10/30/98 10:48 |
