The JTAG-SMT1 is a compact, complete and fully self-contained surface-mount programming module for Xilinx FPGAs. It can be accessed directly from all Xilinx tools, including iMPACT, Chipscope, and EDK. The module can be loaded directly onto a target board and reflowed like any other component.

The JTAG-SMT1 uses a 3.3V main power supply and a separate Vref supply to drive the JTAG signals. All JTAG signals use high speed, 24mA, three-state buffers that allow signal voltages from 1.8V to 5V and bus speeds of up to 30MBit/sec. JTAG signals are actively driven only during a programming event and are otherwise held in high-impedance, so the JTAG bus can be shared with other devices.

• Small, complete, all-in-one JTAG programming solution for Xilinx FPGAs
• Single 3.3V supply
• Separate Vref drives JTAG signal voltages; Vref can be any voltage between 1.8V and 5V.
• High-Speed USB2 port that can drive JTAG/SPI bus at up to 30Mbit/sec
• Able to drive JTAG bus at up to 30Mbit/sec
• JTAG/TCK frequency settable by user
• Compatible with all Xilinx tools
• Small form-factor surface-mount module can be directly loaded on target boards
• Uses micro-AB USB2 connector
• Same circuit is available as a stand-alone programming cable; see Digilent’s JTAG-HS1.

The SMT1 module is CE certified and fully compliant with the RoHS and REACH directives. It uses a standard Type-A to Micro-USB cable, also available from Digilent.

The JTAG signals can be connected directly to the corresponding FPGA signals as shown. For best results, the module should be mounted adjacent to the edge of the host PCB over a ground plane. Although signal traces may be run on top of the host PCB beneath the SMT1, it is recommended the area immediately beneath the SMT1 be kept clear. For highest speed JTAG operation, impedance between the SMT1 and FPGA should be kept below 100 Ohms.

In addition to working seamlessly with all Xilinx tools, the SMT1 is supported by Digilent’s Adept software and the Adept SDK (the SDK can be freely downloaded from Digilent’s website). Adept includes a full-featured programming environment, and a set of public APIs that allow user applications to directly drive the JTAG chain.

Using the SDK, custom applications can be created to drive JTAG ports on virtually any device. The SDK also supports SPI ports, allowing applications to drive any SPI device using SPI Mode 0 or Mode 2. Please see the Adept SDK reference manual for more information.