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Altera_Forum
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10 years ago

JTAG Tolerence for MAX5 Device 5M2210Z

I am using Max5 5M2210Z device in one of my projects. In this I am configuring Bank1 voltage level as 1.8V. Since JTAG is also going to the bank1, the JTAG level should be 1.8V too. I want to...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

Look at the dc and switching characteristics for max v devices' 'dc and switching characteristics for max v devices (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/hb/max-v/mv51003.pdf) for Max V. Yes the pins will tolerate 3.3V. However, if you're operating a bank at 1.8V the recommended max level is 1.89V. Persistent over-driving of a pin could result in damage - eventually.

However, what is your BMC (?) going to make of the 1.8V TDO signal driven towards it? It's expecting a 3.3V logic levels, probably with a minimum V_high threshold of 2.2 to 2.5V. What's it going to make of a 1.8V logic high?

My suggestion - use level translators.

Cheers,

Alex