The JTAG connections on the FPGA are wired directly to the expansion connector MC1 on the XEM8350 to facilitate FPGA configuration and ChipScope usage using a Xilinx JTAG cable. The JTAG interface presented at MC1 is a 1.8-V interface corresponding to the FPGA JTAG I/O voltage. An appropriate connector (such as a 2mm connector compatible with the Xilinx JTAG cable) would need to be wired on the peripheral attached to the XEM8350. Our BRK8350 has this connector and may be used as a reference.

According to the Xilinx documentation (UG570), the FPGA includes internal pull-up resistors on TMS and TCK.

JTAG Cables

The USB interface on FrontPanel-enabled devices provides FrontPanel-based FPGA configuration and communication only. This interface is not available for JTAG access and is not compatible with the vendor tools for JTAG communication (e.g. the Xilinx Vivado Integrated Logic Analyzer or Intel’s Quartus SignalTap).

A vendor-supported JTAG cable is required to interface with the JTAG connector and provide tool access to JTAG.

The following JTAG cables are available with connectors compatible with the connector on the breakout board:

XilinxPlatform Cable USB IIAll Revisions
DigilentJTAG-HS3BRK8350 Rev GXX and Later