Altera_Forum
Honored Contributor
Honored ContributorALT_INBUF_DIFF in cycloneII
is possible in cycloneII device use 2 pins INPUT for differential rs422 signal? In quartus2 the differential buffer for cyclone2 is not allowed!
Forum Discussion
Altera_ForumHonored Contributor
Honored ContributorYes, the LVCMOS/LVTTL pins should reach the high level for 3.3V if you power the bank with 3.3V but tell Quartus you're using 2.5V.
That said, I have the strong feeling that setting pins to LVDS and powering the bank at 3.3V won't do what you need. You really need to take a look at how your "modified" RS-422 looks at the electrical level and how LVDS looks like at the electrical level.
