To ensure the JTAG interface on your board always works reliably, it’s important to ensure it is optimally designed. In this series of videos, we’ll share some hints, tips, and best practices for getting that right.

You will learn what high-speed terminations are required, the best pinouts to use to minimise the dangers of crosstalk, a practical method for confirming you’ve achieved good signal integrity, and how to set up a Test Reset Sequence to ensure your chain is always reliably initialised.

Video 1

  • How to distribute ground connections in a multi-TAP system
  • Best pinouts for the JTAG signals
  • The required high-speed terminations

Video 2

  • Measuring DC voltages with the XJLink2
  • Checking the JTAG chain’s DC continuity & pull-resistors

Video 3

  • Assigning a Test Reset signal to the pin map
  • How to create a Test Reset Sequence
  • Why a Test Reset Sequence is important

Video 4

  • Checking your JTAG chain’s basic functionality using JTAG Chain Debugger
  • Timing adjustment with AutoSkew
  • Tips on resolving problems with the JTAG chain’s functionality

Video 5

  • Debugging broken JTAG chains

Video 6

  • Checking your JTAG chain’s high-speed performance
  • Finding a device’s guaranteed maximum TCK frequency from its BSDL file

Video 7

  • Soak tests for finding intermittent problems caused by sub-optimal signal integrityFine-tuning signal integrity by adjusting slew rate and target terminations for JTAG signals
JTAG Chain Setup

Introduction
8:22
DC Checks
3:50
Test Reset Sequences
5:15
Chain Checking
5:39
Scan ID Codes
2:25
Using “Get Max TCK”
3:58
Final Checks
3:00
Downloads