NAT-JSM JTAG Switch Module for flexible testing and diagnostic

Flexible testing and diagnostic JTAG switch module to accelerate the design, prototyping and operation of MicroTCA systems. It provides JTAG vector testing of all slots in a system using just one module. The NAT-JSM can be configured using the onboard FPGA through the front panel to suit almost any existing JSM system connector, as long as it is based on the AMC connector layout. The module can detect whether it has been inserted into an AMC, MCH or JSM slot and only turns on its output drivers if it detects a JSM slot.

The NAT-JSM has four arbitrated master ports and supports up to 16 secondary ports. By default, the NAT-JSM automatically arbitrates the JTAG master port, the slave port is selected by the TAP controller (default) or by a rotary switch or web interface. The module provides transparent communication between the master and a selected secondary port.

The NAT-JSM module front panel features a standard JTAG programming header and mini USB connector for maximum compatibility and to improve the flexibility of design processes. A hexadecimal rotary switch on the front panel enables you to select the programming target when using one of these interfaces, providing a manual override of the automatic arbitration of the JTAG slave. The same can be achieved by configuring the NAT-JSM through the web interface of the NAT-MCH.

The NAT-JSM can also programmed using a server side application on the NAT-MCH, which supports the Xilinx Virtual Cable (XVC) protocol as used by the Xilinx Vivado or ISE design suites.


Technical Description

  • AMC JTAG Switch module, full size or mid size form factor
  • Altera Cyclone III FPGA subsystem processor
  • JTAG download via MCH through Ethernet
  • JTAG programming connector at front panel
  • Automatic arbitration between JTAG Masters
  • Target selection through JTAG information
  • Overrule of automatic operation and dedicated selection of JTAG target by front panel elements
  • Multiple JSM pinout configurations via FPGA
  • 0°C .. +50°C operating temperature range
  • 2 years warranty

Order Information


JTAG Switch, mid size


JTAG Switch, full size

Technical Documentation

NAT-JSM data sheet

NAT-JSM user manual