Digilent JTAG SMT2 NC – Surface-mount Programming Module

• Small, complete, all-in-one JTAG programming/debugging solution for Xilinx FPGAs
• Compatible with all Xilinx Tools
• Compatible with IEEE 1149.7-2009 Class T0 – Class T4 (includes 2-Wire JTAG)

The Joint Test Action Group (JTAG)-SMT2-NC is a compact, complete, and fully self-contained surface-mount programming module for Xilinx field-programmable gate arrays (FPGAs). The module can be accessed directly from all Xilinx Tools, including iMPACT, ChipScope™, eFuse, Vivado, and EDK. Users can load the module directly onto a target board and reflow it like any other component.

The JTAG-SMT2-NC 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 up to 30MBit/sec. The JTAG bus can be shared with other devices as the SMT2-NC signals are held at high impedance, except when actively driven during programming. The SMT2-NC module is CE certified and fully compliant with EU RoHS and REACH directives. The module routes the USB D+ (DP) and D- (DM) signals out to pads, providing the system designer with the ability to choose the type of USB connector and its location on the system board.

Users can connect JTAG signals directly to the corresponding FPGA signals, as shown in Fig. 1. For best results, mount the module over a ground plane on the host PCB. Although users may run signal traces on top of the host PCB beneath the SMT2-NC, Digilent recommends keeping the area immediately beneath the SMT2-NC clear.

Note: Keep the impedance between the SMT2-NC and FPGA below 100 Ohms to operate the JTAG at maximum speed.

The SMT2-NC improves upon the SMT1 with the addition of three general-purpose I/O pins (GPIO0 – GPIO2) and support for interfacing IEEE 1149.7-2009 JTAG targets in both 2 and 4-wire modes.

In addition to supporting JTAG, the JTAG-SMT2-NC also features eight highly configurable Serial Peripheral Interface (SPI) ports that allow communication with virtually any SPI peripheral (see Fig. 2). All eight SPI ports share the same SCK, MOSI, and MISO pins, so users may enable only one port at any given time. Table 1 summarizes the features supported by each port. The SMT2-NC supports SPI modes 0, 1, 2, and 3.