Figure 2-10 Daisy-Chained Jtag Connection With Tck Buffers - ARM DSTREAM-ST System And Interface Design Reference Manual

This solution prevents the two TCK branches from interacting and ensures good signal integrity with
minimal overshoot. The buffers and series termination resistors should be placed as close as possible to
the T-junction of the TCK signal.
The only disadvantage to this solution is that it causes some skew between the TDI/TMS and TCK
signals. It might be beneficial to use the same type of buffers on the TDI and TMS signals as on the
TCK signals, for example:
ARM 100893_0100_00_en
JTAG
CONNECTOR
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2 ARM

Figure 2-10 Daisy-chained JTAG connection with TCK buffers

Non-Confidential
DSTREAM-ST target interface connections
®
2.6 About JTAG port buffering
ARM
Processor/ASIC
TDI
TMS
TCK
TDO
ARM
Processor/ASIC
TDI
TMS
TCK
TDO
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