Sunday, March 25, 2012

FPGA Editor Tutorial 1: Check routability between pins

You may have seen warning messages from map or par like the one below:

Warning:LIT:683 - DSP48E1 symbol
   "Inst_mult" has one or more CE pins driven by BUFG/BUFH/BUFR. This can lead to an un-routable situation.

These warning messages make you wonder if this "un-routable situation" is due to the physical layout and/or lack of routing resources in the device or some DRC rules in the software to promote best practice. The quickest and most authoritative way to find out the answer is to check it out in FPGA Editor. Below are step-by-step instructions on how to do that using BUFG driving DSP CE pin as an example:

Tuesday, January 24, 2012

Floating Point Algorithm Development Made Easy in System Generator

System Generator 13.3 added support for bit and cycle accurate, single, double and custom precision-floating-point on many blocks in the Xilinx Blockset. It now has a new "Floating-Point" library under "Xilinx Blockset" in the "Simulink Libary Browser", which lists all blocks supporting floating point numbers (see the "Floating Point Library in Xilinx Blockset" snapshot below).