BSDL Files

BSDL Files are text files which specify the behaviour of JTAG-compliant devices. They are provided by the device manufacturer and can usually be found in the support section of manufacturer websites. Some manufacturers require you to register and log in, or to sign an NDA to be able to download these files, however if a device is JTAG-compliant the manufacturer will be able to make the file available to their customers.

The BSDL file contains a list of the pins on the JTAG device and specifies the capabilities of each pin (e.g. input, output, or bidirectional.) The file also contains details of which bits in the boundary scan register of the device correspond to which pin, and the overall capabilities of the device itself, including specifying the JTAG pins of the device.

The BSDL file syntax itself is closely related to VHDL.

Although XJDeveloper supports editing of BSDL files, XJTAG does not recommend editing BSDL files by hand unless you are experienced with the syntax. A full explanation of BSDL is beyond the scope of this help system - if you need to learn more you should refer to the IEEE 1149.1 standard, which can be purchased from the IEEE website.