39.5.1 Related JTAG Files

To implement BST, all JTAG test tools will require a Boundary Scan Description Language (BSDL) file. BSDL is a subset of VHDL (VHSIC Hardware Description Language) and is described as part of IEEE Std. 1149.1. The device-specific BSDL file describes how the standard is implemented on a particular device and how it operates.

The BSDL file for a particular device includes the following:
  • The pinout and package configuration for the particular device
  • The physical location of the TAP pins
  • The Device ID register and the device ID
  • The length of the Instruction Register
  • The supported BST instructions and their binary codes
  • The length and structure of the Boundary Scan register
  • The boundary scan cell definition

Device-specific BSDL files are available at Microchip’s web site, www.microchip.com. The name for each BSDL file is the device name and silicon revision. For example, PIC18F57Q83_VQFN.BSD, is the BSDL file for the PIC18F57Q83 in the VQFN package.