All Virtex® and Spartan® FPGAs include many block RAMs. Even the smallest Virtex device has dozens of block RAMs, larger devices have hundreds, and the largest, the XC5VSX240T, has 1032. Because many designs do not require all of these block RAMs, this paper explores alternate uses for these functional blocks.
This poster describes the implementation of a 400-MHz frequency counter in an XC4002XL FPGA. In addition to speed, other objectives were low power and efficient resource utilization. These objectives were met using a semi-synchronous design technique where pairs of flip-flops operate as synchronous state machines that are cascaded asynchronously. XC4OOOXL… (More)