Virtex-E EM

Due to rapidly expanding networking industry demands, there is a corresponding need for faster and faster search capabilities within Content Addressable Memory (CAM) devices. Every year new CAM devices emerge on the market. These devices have excellent capabilities and options, but they require an accompanying interface. Virtex® devices have all the necessary features to interface with high-speed Cams. This document describes a Virtex CAM controller for the Search Engine (a type of CAM device) from Lara Networks.

CAM (Content Addressable Memory) offers increased data search speed. In various applications based on CAM, there are differing requirements for data organization and read/write performance. The innovative design described in this application note is suited for small embedded CAMs with high-speed match and write requirements. The reference design is built using the true Dual-Port block SelectRAM™+ feature of Virtex® FPGAs. Application Note XAPP201, "An Overview of Multiple CAM Designs in Virtex Devices," discusses the diverse solutions available when implementing CAM while introducing the specific solution described in this application note.

In embedded systems, designers can reduce component count and increase flexibility by using a microprocessor to configure an FPGA. C code illustrates the use of either Slave Serial or SelectMAP mode. CPLD design files illustrate a synchronous interface between processor and FPGA.

This application note describes how the existing dual-port block memories in the Spartan®-II and Virtex® families can be used as Quad-Port memories. This essentially involves a data access time (halved) versus functionality (doubled) trade-off. The overall bandwidth of the block memory in terms of bits per second will remain the same.

This application note describes the transformation of multiple synchronous serial data streams to parallel data through a multi-channel serial-to-parallel converter.

This application note describes how to use Virtex™-E Bus Low Voltage Differential Signaling (BLVDS) technology in high-performance multipoint applications. BLVDS extends the benefits of standard LVDS into multipoint configuration supporting bidirectional backplanes. Spice simulation results show that the multipoint configuration described in this application note can operate up to 200 MHz.

The Xilinx high-performance CPLD, FPGA, and configuration PROM families provide in-system programmability, reliable pin locking, and JTAG boundary-scan test capability. This powerful combination of features allows designers to make significant changes and still keep the original device pin-outs, which eliminates the need to re-tool PC boards.

This application note describes techniques for remote reconfiguration of FPGAs through an Ethernet port.

This application note discusses the configuration and programming options for Xilinx Complex Programmable Logic Device (CPLD), Field Programmable Gate Array (FPGA), and PROM families and demonstrates some of the most popular configuration methods used for each family. This document includes configuration quick start guidelines for the Virtex™, Spartan™, XPLA3, XC9500, and XC18V00 families.

MicroBlaze™ has the ability to use its dedicated FSL bus interface to integrate a customized IP core into a MicroBlaze soft processor-based system. This document describes possible methods to include customized IP cores into an SCP-based design.

This application note describes in-circuit partial reconfiguration of RocketIO™ transceiver attributes using the Virtex-II Pro™ internal configuration access port (ICAP). The solution uses a Virtex-II Pro device with an IBM PowerPC™ 405 (PPC405) processor to perform a partial reconfiguration of the RocketIO multi-gigabit transceivers (MGTs) pre-emphasis and differential swing control attributes. These attributes must be modified to optimize the MGT signal transmission prior to and after a system has been deployed in the field. This solution is also ideal for characterization, calibration, and system testing.

Most Xilinx CPLDs, PROMs, and FPGAs have an IEEE Standard 1149.1 (JTAG) port. Xilinx devices with a JTAG port are in-system programmable (ISP) through the JTAG port. The ISP feature is beneficial for fast prototype development. This application note describes a short list of considerations needed to get the best performance from your ISP designs.

When designing digital systems, there is often a requirement to synchronize incoming data and clock signals with an internal system clock, i.e., the internal and external clock are at exactly the same frequency, but due to variable backplane, board, or application-specific standard product (ASSP) delays, the phase relationship is not known. The circuit described in this application note addresses this issue for both single traces and data buses up to 210 MHz in a Virtex®-II -5 device. The speed limitation is imposed by the maximum frequency that can be accepted by the Digital Clock Manager (DCM), in a mode where it is capable of providing both a new clock and a new clock shifted by 90 degrees.

Package drawing.

This white paper describes a rarely noticed design technique that can make a difference in the size and the performance of your FPGA design. Control signals on FPGA flip-flops have a built-in priority. If you can learn to write code that is sympathetic to the priorities, the results will be rewarding. This white paper provides some simple VHDL and Verilog examples to explain key points.

Surface Mount Technology (SMT) packages include the leaded family packages (Quad Flat Pack (QFP) and Plastic Leaded Chip Carrier (PLCC)) and the Ball Grid Array (BGA) packages. SMT rework can be necessary for any of the following reasons: assembly related defects, such as shorts, opens, wrong orientation, and solder ball defects; device/package related defects/failure analysis; and engineering change or system upgrade.

The variable-input look-up table (LUT) architecture has been a fundamental component of the Xilinx Virtex architecture first introduced in 1998. This unique architecture enables flexible implementation of any function with eight variable inputs, as well as implementation of more complex functions. In addition to being optimized for 4-, 5-, 6-, 7-, and 8-input LUT functions, the architecture is designed to support 32:1 multiplexers and Boolean functions with up to 79 inputs. The Virtex architecture enables users to implement these functions with minimal levels of logic. By collapsing levels of logic, users can achieve superior design performance. This performance leadership is validated by benchmarks that show Virtex with an average 38% performance leadership over alternative programmable logic architectures.