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Altera_Forum
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19 years ago

JTAG Hub, Avalon JTAG UART

Hi, I'm looking for documentation about how to communicate with an Avalon JTAG UART from an external microcontroller. I have read ug_virtualjtag and thus know how i could implement communi...
Altera_Forum's avatar
Altera_Forum
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19 years ago

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originally posted by kawk@Sep 3 2006, 02:03 AM

instructions with code 0xc and 0xe appear quite often

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Ah, I think I understand how to access virtual JTAG devices: With 0xC or 0xE in the Cyclone's IR, during a following select/capture/shift/update DR cycle, the chain of virtual devices appears instead of the Cyclone in the real chain. Furthermore, with 0xE, the virtual devices select IR, not DR as in the real chain.

This explanation may not be the full truth, but it is probably close. Are there any official names for these JTAG instructions 0xC and 0xE? The other questions from my original posting remain unanswered (yet)...

Kolja