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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!
Altera_ForumHonored Contributor
Honored ContributorHi Thielam,
I know the difference between RS232 and RS422. I also know that RS422 is not 0 to 3V3. Maybe you should read: http://www.bb-elec.com/bb-elec/literature/tech/485appnote.pdf It gives you all the information differential signaling, voltage levels, common mode, grounding, and so on. One things is for sure: You should not connect RS422 directly to your FPGA. Success, Ton
