An Overview of Multiple CAM Designs in Virtex Family Devices
Xilinx Family · 1999
Summary Flexible CAMs (Content Addressable Memory) are implemented in Virtex™ family devices by taking advantage of the reprogrammability of the basic LUT as a Shift Register (SRL16) or as a SelectRAM+™ memory and the fast carry logic chain. Although CAMs are also feasible in Spartan™ and XC4000X devices, this application note concentrates on Virtex™ and Virtex™-E devices. The flexibility of Virtex devices is a key advantage in designing a CAM, with the application determining the best implementation. As an overview, this application note references XAPP202 “CAM Designs in ATM Applications”, XAPP203 “Designing Flexible, Fast CAMs with Virtex Family FPGAs”, and XAPP204 “Using Virtex Block SelectRAM+ for High Performance Read/Write CAMs”.