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Altera_Forum
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14 years ago

100 pF filter capacitor on TMS programming pin

Hello everybody, Alter reccommends the use of a 10k pullup resistor to VDD on the TMS JTAG pin to keep the input at VDD when in ioperational mode. We are also considering a 100pF capaci...
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Altera_Forum
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14 years ago

Why 100pF for TMS and not for TDI? How about TCK, the only edge sensitive JTAG signal?

I would primarly suggest overvoltage protection for all JTAG pins, e.g. using high speed ESD diodes. In some situation, a small parallel capacitance for TCK seems to be necessary for reliable operation.