In-Circuit Verification

As a final test, you can verify how your design performs in the target application. In-circuit verification tests the circuit under typical operating conditions. Because you can program your Xilinx FPGAs repeatedly, you can easily load different iterations of your design into your device and test it in-circuit. To verify your design in-circuit, download your design bitstream into a device with the Xilinx XChecker cable.

NOTE

For information about Xilinx cables and hardware, see the Hardware User Guide.

Design Rule Checker

Before generating the final bitstream, it is important to use the DRC option in BitGen to evaluate the NCD file for problems that could prevent the design from functioning properly. DRC will be invoked automatically unless you use the -d option.

Xilinx Design Download Cables

Xilinx provides either the Parallel Cable III or the XChecker cable, depending on which development system you are using. To download your design, you must create a configuration bitstream using BitGen.

You can use the XChecker cable to read back and verify configuration data. Detailed cable connection and daisy-chain information is provided in the Hardware Debugger Reference/User Guide.

NOTE

The Xilinx Parallel Cable III can be used for FPGA and CPLD design download and readback, but it does not have a design verification function.

With the XChecker cable, you can use the Hardware Debugger Pick function to take snapshots of the circuit at specific clock cycles. You can obtain these snapshots by performing serial readback of the nodes during in-circuit operation. With the Hardware Debugger software, you can speed up your analysis by limiting the readback bitstream to only those nodes and clock cycles in which you have interest.

You can also use the XChecker cable to probe your design after you download it. Probing internal nodes allows you to pinpoint the location of any design problems.

Use the XChecker cable when you do not want to specify additional IOBs and routing resources on your Xilinx FPGA for probing. This allows you to decide how you want to probe after you have downloaded your design.